1 00:00:05,600 --> 00:00:08,680 There are still parts of our planet... 2 00:00:08,680 --> 00:00:10,120 ..yet to be explored. 3 00:00:17,600 --> 00:00:19,000 Descending! 4 00:00:19,000 --> 00:00:22,480 These are remote and unforgiving places... 5 00:00:23,680 --> 00:00:24,760 I'm in. 6 00:00:24,760 --> 00:00:26,880 ..and the journey to reach them... 7 00:00:26,880 --> 00:00:30,200 We're in very real danger of getting trapped here. 8 00:00:30,200 --> 00:00:32,480 ..will push me and a team of explorers... 9 00:00:32,480 --> 00:00:34,640 Ugh. Ugh, ugh. 10 00:00:34,640 --> 00:00:35,680 ..to the limit. 11 00:00:35,680 --> 00:00:37,920 HE SHOUTS 12 00:00:37,920 --> 00:00:39,480 It looks like he's coming back. 13 00:00:43,400 --> 00:00:44,760 The reward... 14 00:00:44,760 --> 00:00:45,840 Amazing! 15 00:00:46,800 --> 00:00:49,280 ..breathtaking new discoveries. 16 00:00:49,280 --> 00:00:53,040 When you're standing in a place that no-one has ever stood before, 17 00:00:53,040 --> 00:00:54,560 it's very, very precious. 18 00:00:55,800 --> 00:00:58,560 This time we're in Mexico. 19 00:00:58,560 --> 00:01:00,200 Somewhere deep in there 20 00:01:00,200 --> 00:01:03,280 is probably the thing I'm most frightened of in the whole world. 21 00:01:04,320 --> 00:01:08,720 I'm entering the supernatural land of the ancient Maya. 22 00:01:08,720 --> 00:01:10,560 Clear rope! 23 00:01:10,560 --> 00:01:14,160 We'll journey underground into a secret underworld... 24 00:01:14,160 --> 00:01:15,480 Look at that! 25 00:01:15,480 --> 00:01:19,360 ..the Maya called The Place Of Fear... 26 00:01:19,360 --> 00:01:21,040 ..to learn how they lived.... 27 00:01:21,040 --> 00:01:24,000 I just feel I've been connected back through time. 28 00:01:24,000 --> 00:01:25,040 ..and died. 29 00:01:25,040 --> 00:01:27,880 It's a skull! There's a human skull! 30 00:01:27,880 --> 00:01:30,320 This is more the kind of fear that I had when I was a kid, 31 00:01:30,320 --> 00:01:32,520 and I was scared of monsters under the bed 32 00:01:32,520 --> 00:01:34,600 and the stuff of nightmares. 33 00:01:48,600 --> 00:01:51,240 I'm in the Yucatan Peninsula in Mexico. 34 00:01:55,920 --> 00:01:59,920 All the way to the horizon, it's just completely flat, 35 00:01:59,920 --> 00:02:03,040 and beyond the realms of the village, forest - 36 00:02:03,040 --> 00:02:04,840 just thick, dense forest - 37 00:02:04,840 --> 00:02:08,760 and underneath that is a peppered latticework of caves, 38 00:02:08,760 --> 00:02:12,040 almost none of which have ever been explored. 39 00:02:14,000 --> 00:02:16,240 Many of these caves are flooded. 40 00:02:17,400 --> 00:02:20,040 I've spent the past month with Robbie Schmittner, 41 00:02:20,040 --> 00:02:22,240 a world-leading cave explorer. 42 00:02:24,360 --> 00:02:28,200 We've been mapping these caves to help scientists better understand 43 00:02:28,200 --> 00:02:30,840 how to protect the precious fresh water they provide. 44 00:02:32,760 --> 00:02:35,040 It completely blows my mind... 45 00:02:35,040 --> 00:02:37,360 ..to think that below... 46 00:02:37,360 --> 00:02:42,800 ..so much of the Yucatan are rooms like this that nobody has ever seen. 47 00:02:42,800 --> 00:02:45,880 HE LAUGHS JOYFULLY 48 00:02:45,880 --> 00:02:48,200 While Robbie continues mapping, 49 00:02:48,200 --> 00:02:52,560 I'm heading further inland to explore a set of special caves. 50 00:02:56,000 --> 00:03:00,280 The caves have played a unique part in the mythology of the ancient Maya 51 00:03:00,280 --> 00:03:02,520 for at least 2,000 years. 52 00:03:06,000 --> 00:03:08,840 The ancient Maya believed these caves were portals 53 00:03:08,840 --> 00:03:14,520 to a supernatural underworld called Xibalba, "The Place Of Fear". 54 00:03:14,520 --> 00:03:16,080 HORN HONKS 55 00:03:17,640 --> 00:03:21,840 The human history here in Yucatan is absolutely fascinating. 56 00:03:21,840 --> 00:03:24,480 I'm not an anthropologist or an archaeologist, 57 00:03:24,480 --> 00:03:26,080 but you've got to say, 58 00:03:26,080 --> 00:03:28,520 it's one of the most exciting places on the planet. 59 00:03:30,440 --> 00:03:34,840 The Yucatan is rich in artefacts left by the ancient Maya, 60 00:03:34,840 --> 00:03:39,080 a civilisation which stretched across Central America. 61 00:03:40,520 --> 00:03:44,760 Scientifically advanced, they were master astronomers and builders... 62 00:03:47,720 --> 00:03:49,840 ..but they had a dark side. 63 00:03:49,840 --> 00:03:53,120 Spiritual beliefs led them to carry out unusual 64 00:03:53,120 --> 00:03:54,960 and often gruesome practices. 65 00:03:56,160 --> 00:03:59,600 Many were performed in these caves. 66 00:03:59,600 --> 00:04:01,800 To get a deeper understanding of the Maya, 67 00:04:01,800 --> 00:04:04,160 I want to explore them and go further into them 68 00:04:04,160 --> 00:04:05,840 than anyone has before. 69 00:04:09,560 --> 00:04:12,000 To help me, I've chosen an elite team. 70 00:04:12,000 --> 00:04:15,120 Underwater camera operator Katy Fraser... 71 00:04:15,120 --> 00:04:18,520 That's very light. That's going to fly. 72 00:04:18,520 --> 00:04:20,360 ..dive supervisor Scott Carnahan... 73 00:04:20,360 --> 00:04:22,160 Who is it? 74 00:04:22,160 --> 00:04:24,440 ..and former Royal Marine Aldo Kane, 75 00:04:24,440 --> 00:04:27,400 who has the challenge of keeping us all safe. 76 00:04:31,680 --> 00:04:34,160 Our journey begins at a secret location. 77 00:04:36,040 --> 00:04:39,440 I'm meeting an archaeologist who'll take me to these caves. 78 00:04:41,160 --> 00:04:42,400 Hey, Memo. 79 00:04:42,400 --> 00:04:45,480 Guillermo De Anda, also known as Memo, 80 00:04:45,480 --> 00:04:48,760 is a world authority on the ancient Maya. 81 00:04:48,760 --> 00:04:51,880 This place is remarkable. 82 00:04:51,880 --> 00:04:54,280 It's unbelievable, isn't it? 83 00:04:54,280 --> 00:04:58,760 This is a sacred cenote for the ancient Maya. 84 00:04:58,760 --> 00:05:01,880 He's spent his career examining the powerful relationship 85 00:05:01,880 --> 00:05:05,000 the Maya had with these caves. 86 00:05:05,000 --> 00:05:06,600 So this is where we're going, down here? 87 00:05:06,600 --> 00:05:08,080 This is where we're going today. 88 00:05:08,080 --> 00:05:10,000 Shall we get the lid off this thing? Yeah. 89 00:05:13,960 --> 00:05:17,240 These ruins date back a few hundred years, 90 00:05:17,240 --> 00:05:21,080 but beneath this tumbled down well is a submerged cave 91 00:05:21,080 --> 00:05:24,680 that's much, much older - 92 00:05:24,680 --> 00:05:29,400 one Memo thinks is a Maya portal to the underworld. 93 00:05:32,880 --> 00:05:37,320 It contains a sinister secret that has helped Memo understand 94 00:05:37,320 --> 00:05:40,200 how the Maya lived and died. 95 00:05:43,840 --> 00:05:46,280 Whoa. 96 00:05:46,280 --> 00:05:49,520 What's that, about 15 or 20 metres down? 97 00:05:49,520 --> 00:05:51,960 Yeah, it's about 15 metres to the water. 98 00:05:53,040 --> 00:05:54,720 Have you ever dived in a well before? 99 00:05:54,720 --> 00:05:58,240 I have never dived in a well before, no. 100 00:06:00,600 --> 00:06:02,720 It's working, so you're going to... Stop. 101 00:06:02,720 --> 00:06:04,840 If we lift this back a bit... 102 00:06:07,160 --> 00:06:08,400 We had to get down the well 103 00:06:08,400 --> 00:06:12,000 and through a hole into the roof of the flooded cave beneath, 104 00:06:12,000 --> 00:06:13,280 all in full dive gear. 105 00:06:13,280 --> 00:06:14,720 Which, erm...? 106 00:06:16,720 --> 00:06:19,760 Are these my cylinders here? Those are my cylinders? Yeah. 107 00:06:21,880 --> 00:06:25,120 Before we dive, there's another cave just minutes away 108 00:06:25,120 --> 00:06:28,000 that Memo also wants me to see - 109 00:06:28,000 --> 00:06:30,320 more easily accessible, 110 00:06:30,320 --> 00:06:34,080 he thinks it has a grisly connection to the well cave. 111 00:06:35,120 --> 00:06:38,120 So, Memo, is it going to be any cooler inside the cave? 112 00:06:38,120 --> 00:06:40,080 Yes. Much, much cooler. 113 00:06:40,080 --> 00:06:41,320 Oh, that is good news. 114 00:06:41,320 --> 00:06:44,560 I tell you, my English blood doesn't like this at all. 115 00:06:44,560 --> 00:06:48,240 I know. Even we Mexicans... 116 00:06:48,240 --> 00:06:51,880 ..feel really, really hot this time of year. 117 00:06:51,880 --> 00:06:54,400 Do many people come down here, Memo? No. 118 00:06:54,400 --> 00:06:58,360 Fortunately this is, like, still very well preserved. 119 00:06:58,360 --> 00:07:02,400 We're stepping right now, Steve, on a Maya stone stairway. 120 00:07:04,680 --> 00:07:07,920 Only a select few know the location of these caves. 121 00:07:07,920 --> 00:07:11,120 Secrecy is their only protection against vandals. 122 00:07:21,240 --> 00:07:23,960 So we're looking at a piece of Maya history. 123 00:07:26,200 --> 00:07:28,520 Seriously, I got a chill that went up the back of my neck 124 00:07:28,520 --> 00:07:30,000 as soon as I saw that. 125 00:07:32,160 --> 00:07:34,000 They look like they were left yesterday. 126 00:07:34,000 --> 00:07:36,360 If you see, we call it Little Hands Cave or Manitas, 127 00:07:36,360 --> 00:07:38,880 because there's a lot of children's hands. 128 00:07:38,880 --> 00:07:40,960 And if you look towards your right... 129 00:07:40,960 --> 00:07:44,480 Whoa, look at those over there! Positive handprints, yeah. 130 00:07:45,920 --> 00:07:47,720 This is really pretty special... Yeah. 131 00:07:47,720 --> 00:07:51,800 ..that these are the handprints of a Mayan child 132 00:07:51,800 --> 00:07:56,080 left over 1,000 years ago... Yes, yes. ..and they're still here, 133 00:07:56,080 --> 00:07:58,880 as crystal clear as if a child just put their hand in paint 134 00:07:58,880 --> 00:08:00,200 and whacked it on the wall. 135 00:08:02,960 --> 00:08:06,400 It's interesting that I've seen prints like this in many caves 136 00:08:06,400 --> 00:08:09,880 around the world, in New Guinea and Borneo and in Europe - 137 00:08:09,880 --> 00:08:12,280 there's clearly something universal 138 00:08:12,280 --> 00:08:14,960 about leaving your mark behind like this. 139 00:08:17,560 --> 00:08:20,640 Do you think that this is like playing? Putting paint? 140 00:08:20,640 --> 00:08:23,280 Or do you think that there could be something more to it than that? 141 00:08:23,280 --> 00:08:25,400 You know, we cannot disregard that possibility, 142 00:08:25,400 --> 00:08:28,040 but I don't think that that was the case, 143 00:08:28,040 --> 00:08:32,000 because right where you are, if we look up... 144 00:08:33,440 --> 00:08:39,920 ..we should find some little feet, maybe a one- or two-year-old. 145 00:08:39,920 --> 00:08:41,360 So there's no way that a child 146 00:08:41,360 --> 00:08:44,200 could have deliberately put their hands and feet up there... Exactly. 147 00:08:44,200 --> 00:08:45,640 ..it had to be done... 148 00:08:46,600 --> 00:08:48,240 ..by someone else, by an adult. 149 00:08:48,240 --> 00:08:50,840 I wish I could find exactly what the purpose 150 00:08:50,840 --> 00:08:54,000 or what the symbolism or what the meaning of that is. 151 00:08:54,000 --> 00:08:58,040 We believe it could be maybe a signature of something... Yeah. 152 00:08:58,040 --> 00:09:03,480 ..or a reminder of an event, or a rite of passage. 153 00:09:04,920 --> 00:09:09,080 These might have been children that were sacrificed afterwards. 154 00:09:09,080 --> 00:09:10,800 It was part of a ritual. 155 00:09:15,520 --> 00:09:19,760 That's an incredibly macabre thought. 156 00:09:19,760 --> 00:09:23,000 We're looking at the handprints of a Mayan child 157 00:09:23,000 --> 00:09:25,240 from well over 1,000 years ago 158 00:09:25,240 --> 00:09:27,920 that may soon after have been sacrificed. 159 00:09:27,920 --> 00:09:29,680 Yes. Oh, yeah. 160 00:09:29,680 --> 00:09:34,560 Yeah, maybe this was the last thing they'd do in their life. 161 00:09:36,120 --> 00:09:39,400 There are over 100 handprints in this cave. 162 00:09:39,400 --> 00:09:41,640 If Memo's theory is correct, 163 00:09:41,640 --> 00:09:45,640 each one could belong to someone who was ritually sacrificed. 164 00:09:49,200 --> 00:09:53,240 There are even prints from children as young as two. 165 00:09:54,200 --> 00:09:56,120 If they were killed here, 166 00:09:56,120 --> 00:09:58,920 their remains are missing from this cave. 167 00:10:05,080 --> 00:10:08,120 Memo believes the flooded cave beneath the well 168 00:10:08,120 --> 00:10:10,640 could hold the key to understanding why. 169 00:10:15,600 --> 00:10:18,040 He's been diving in this well cave before, 170 00:10:18,040 --> 00:10:20,440 and believes the site had a special 171 00:10:20,440 --> 00:10:22,320 and grisly significance for the Maya. 172 00:10:24,120 --> 00:10:27,960 He thinks they came to carry out human sacrifices. 173 00:10:32,880 --> 00:10:34,920 That's pretty scary. 174 00:10:34,920 --> 00:10:39,160 Effectively, we're going into a sunken mausoleum. 175 00:10:39,160 --> 00:10:41,800 It is the kind of stuff that wakes you up in the middle of the night 176 00:10:41,800 --> 00:10:43,040 in a cold sweat. 177 00:10:45,080 --> 00:10:46,880 It is the stuff of nightmares. 178 00:10:49,760 --> 00:10:52,600 It's not ideal to set up here because of the distance. 179 00:10:52,600 --> 00:10:55,240 We'll work that out, or I can pull them in. 180 00:10:55,240 --> 00:10:57,480 Aldo's rigged a frame that will lower us 181 00:10:57,480 --> 00:10:59,680 and our equipment into the cave 182 00:10:59,680 --> 00:11:02,920 and, just as importantly, get us back out again. 183 00:11:02,920 --> 00:11:05,000 It is a complex operation. 184 00:11:05,000 --> 00:11:10,240 We've got four divers in a confined space in an overhead environment, 185 00:11:10,240 --> 00:11:12,440 in a cave, and you're on the end of ropes. 186 00:11:12,440 --> 00:11:14,720 We can't get to you that quickly. 187 00:11:14,720 --> 00:11:16,240 In fact, we probably won't get to you - 188 00:11:16,240 --> 00:11:18,960 it'll be down to you to self-rescue to the ropes. 189 00:11:21,240 --> 00:11:23,040 For once on an expedition, 190 00:11:23,040 --> 00:11:26,120 I'm not thinking about the logistical problems. 191 00:11:26,120 --> 00:11:29,160 OK, lean out a bit further. Try and get out past the edge. 192 00:11:29,160 --> 00:11:31,560 Right, was there anything that needed changed on that? 193 00:11:31,560 --> 00:11:33,760 Nope, negative. 194 00:11:33,760 --> 00:11:35,640 Everyone happy with how that went? 195 00:11:35,640 --> 00:11:41,200 These caverns are living graveyards, living mausoleums. 196 00:11:41,200 --> 00:11:43,560 Two metres in the water. 197 00:11:43,560 --> 00:11:45,960 This is more the kind of fear that I had when I was a kid, 198 00:11:45,960 --> 00:11:48,440 and I was scared of monsters under the bed 199 00:11:48,440 --> 00:11:50,480 and creatures in the cupboard. 200 00:11:50,480 --> 00:11:54,120 It's that fear of the unknown, 201 00:11:54,120 --> 00:11:57,000 and darkness and death, 202 00:11:57,000 --> 00:11:59,720 and all the things that haunt us most. 203 00:11:59,720 --> 00:12:01,040 Katy? 204 00:12:04,280 --> 00:12:05,960 The Maya feared these caves 205 00:12:05,960 --> 00:12:09,560 because they believed the gods responsible for human suffering 206 00:12:09,560 --> 00:12:11,000 lived in them. 207 00:12:12,440 --> 00:12:17,360 They offered these gods gruesome sacrifices to try and appease them. 208 00:12:19,520 --> 00:12:21,360 HIS VOICE ECHOES: Descending! 209 00:12:25,000 --> 00:12:27,360 How far out are we, Scott? More, Aldo. 210 00:12:27,360 --> 00:12:30,720 OK, Steve, we're going to lower it on the working line. So get down. 211 00:12:49,800 --> 00:12:52,960 Diver on the bottom? Diver's floating. 212 00:13:07,040 --> 00:13:08,080 Stop. 213 00:13:08,080 --> 00:13:09,080 All stop. 214 00:13:14,840 --> 00:13:16,960 Guillermo? Guillermo, are you OK? 215 00:13:16,960 --> 00:13:19,240 Can you hear me well? Yeah, I can hear you. 216 00:13:19,240 --> 00:13:22,960 Take your time and get your systems right. 217 00:13:22,960 --> 00:13:25,720 OK. Moving in closer. 218 00:13:30,560 --> 00:13:32,680 We've been granted permission to dive here 219 00:13:32,680 --> 00:13:36,080 on the understanding that we don't touch anything we find. 220 00:13:40,400 --> 00:13:42,480 Guillermo, I see something. 221 00:13:42,480 --> 00:13:43,680 OK. 222 00:13:43,680 --> 00:13:45,040 It's a horn. 223 00:13:45,040 --> 00:13:47,720 We're just descending down... 224 00:13:47,720 --> 00:13:49,400 ..underneath... 225 00:13:49,400 --> 00:13:51,600 ..the daylight... 226 00:13:51,600 --> 00:13:52,960 ..of the well above. 227 00:13:55,200 --> 00:13:58,440 That is the skull of a bull. 228 00:13:59,640 --> 00:14:01,400 What's this on the teeth, here? 229 00:14:01,400 --> 00:14:04,520 Steve, I really don't know. 230 00:14:04,520 --> 00:14:06,200 It looks like gold. 231 00:14:08,440 --> 00:14:11,440 There is no natural goal here in the Yucatan, is there? 232 00:14:11,440 --> 00:14:14,320 No. No, Steve. 233 00:14:14,320 --> 00:14:17,320 There is no gold in Yucatan. 234 00:14:19,280 --> 00:14:22,200 The unusual appearance of the teeth could be due to 235 00:14:22,200 --> 00:14:27,040 natural discoloration caused by the diet of the animal, 236 00:14:27,040 --> 00:14:30,000 and this skull can't be from the time of the ancient Maya, 237 00:14:30,000 --> 00:14:31,960 because we know they didn't have cattle. 238 00:14:34,200 --> 00:14:36,240 OK. What do you think? Shall we go down? 239 00:14:36,240 --> 00:14:37,440 Let's go for it. 240 00:14:46,160 --> 00:14:48,600 Look at that, Memo, it's a pot! 241 00:14:48,600 --> 00:14:49,680 It's beautiful. 242 00:14:53,200 --> 00:14:55,320 How old do you think this might be? 243 00:14:55,320 --> 00:14:58,320 This might be 1,000 years old, 244 00:14:58,320 --> 00:15:01,320 and look how well-preserved it is. 245 00:15:01,320 --> 00:15:02,320 Wow. 246 00:15:07,320 --> 00:15:10,560 They weren't just dropped in here by accident. 247 00:15:10,560 --> 00:15:15,000 No. No, Steve, it would be too many accidents. 248 00:15:16,400 --> 00:15:18,320 What would be in these pots? 249 00:15:18,320 --> 00:15:23,760 Usually food or maybe a sacrificed animal. 250 00:15:27,000 --> 00:15:30,520 Maya pottery was extremely fragile. 251 00:15:30,520 --> 00:15:35,560 What we found suggests someone swam down and placed it here intact. 252 00:15:39,320 --> 00:15:40,800 Guillermo, what's that? 253 00:15:42,800 --> 00:15:44,480 Oh, where is it? 254 00:15:44,480 --> 00:15:47,080 Just...just below you now, in your torchlight. 255 00:15:47,080 --> 00:15:48,320 Just there. 256 00:15:48,320 --> 00:15:50,960 It's a skull. There's a human skull. 257 00:15:56,280 --> 00:16:00,120 There's something very unsettling about the sight of a human skull. 258 00:16:02,680 --> 00:16:09,240 It might belong to somebody that was high-class, elite... 259 00:16:09,240 --> 00:16:10,680 How do you know that? 260 00:16:10,680 --> 00:16:14,080 If you look closely at the teeth, 261 00:16:14,080 --> 00:16:19,600 you can see they have been modified for symbolic purposes 262 00:16:19,600 --> 00:16:22,440 when this person was alive. 263 00:16:24,880 --> 00:16:27,640 Memo thinks the person was decapitated, 264 00:16:27,640 --> 00:16:30,840 and the head or skull then used as an offering. 265 00:16:34,600 --> 00:16:36,920 There are bones everywhere. 266 00:16:38,520 --> 00:16:45,400 Arms, legs, ribcages, feet - all given to appease the gods. 267 00:16:47,640 --> 00:16:53,720 This is without any doubt a very sacred place. 268 00:16:58,440 --> 00:17:03,880 Ancient Maya artwork shows that sacrifices were incredibly gruesome. 269 00:17:03,880 --> 00:17:06,160 Flesh was stripped from dead bodies, 270 00:17:06,160 --> 00:17:09,680 and they even inflicted terrible injuries on themselves 271 00:17:09,680 --> 00:17:11,800 to offer up their own blood. 272 00:17:15,160 --> 00:17:19,200 What's that? What have you got? It's a complete body. 273 00:17:23,200 --> 00:17:25,640 How he got there, I wonder... 274 00:17:26,840 --> 00:17:30,520 Memo has come across this sort of thing before. 275 00:17:30,520 --> 00:17:34,800 I have seen evidence of cut marks, very deep, 276 00:17:34,800 --> 00:17:37,600 either on the ribs... 277 00:17:37,600 --> 00:17:40,040 ..or either in the sternum. 278 00:17:41,240 --> 00:17:45,960 That tells me that a knife got in that body 279 00:17:45,960 --> 00:17:49,560 and very skilfully ripped apart the heart. 280 00:17:49,560 --> 00:17:53,800 Sometimes this happened when the victim was still alive. 281 00:17:57,760 --> 00:18:00,720 They ripped out their hearts and they were still alive? 282 00:18:00,720 --> 00:18:02,040 Yes. 283 00:18:08,160 --> 00:18:12,000 Those are... Those are under an overhang. 284 00:18:12,000 --> 00:18:14,360 Yes. It looks like they were placed there, Memo. 285 00:18:17,640 --> 00:18:19,800 There's no current in this chamber, 286 00:18:19,800 --> 00:18:23,400 and all the bones are arranged close to each other. 287 00:18:23,400 --> 00:18:26,320 They may have been put here deliberately - 288 00:18:26,320 --> 00:18:28,000 no easy task. 289 00:18:33,680 --> 00:18:36,120 It was hard enough for us to get in 290 00:18:36,120 --> 00:18:38,800 with modern ropes and climbing equipment. 291 00:18:41,000 --> 00:18:43,440 They would have had to hold their breath 292 00:18:43,440 --> 00:18:46,280 and swim down to place this offering here, 293 00:18:46,280 --> 00:18:48,920 to push and prod it into this position. 294 00:18:58,560 --> 00:19:02,600 Everywhere you look, there's another body - 295 00:19:02,600 --> 00:19:07,200 another skull...grinning at you from the darkness. 296 00:19:15,400 --> 00:19:18,960 This place has so many stories to tell. 297 00:19:18,960 --> 00:19:22,320 So many secrets, so many mysteries... 298 00:19:22,320 --> 00:19:27,040 Everywhere you look, the memories of an uncomfortable ritual past. 299 00:19:27,040 --> 00:19:30,760 This place has horrifying nightmare significance. 300 00:19:32,600 --> 00:19:36,240 The cruelty the Maya engaged in to appease the gods of Xibalba 301 00:19:36,240 --> 00:19:38,440 is evident everywhere. 302 00:19:38,440 --> 00:19:41,960 These barbaric acts seem at odds with the sophistication 303 00:19:41,960 --> 00:19:43,280 of their culture. 304 00:19:46,400 --> 00:19:52,800 What we hear about the ancient Maya is all quite macabre. 305 00:19:52,800 --> 00:19:58,600 It's all about human sacrifice and kind of quite grisly. 306 00:19:59,680 --> 00:20:03,480 You know, the first time you encounter these remains, 307 00:20:03,480 --> 00:20:04,920 it's very emotional. 308 00:20:06,120 --> 00:20:07,440 I have kids. 309 00:20:07,440 --> 00:20:11,200 And you try to understand why they do that. 310 00:20:11,200 --> 00:20:16,440 There is...these two different... 311 00:20:16,440 --> 00:20:18,720 ..approaches to the Maya. 312 00:20:18,720 --> 00:20:21,720 One of them is these beautiful buildings, 313 00:20:21,720 --> 00:20:25,400 the great astronomy and science they develop, 314 00:20:25,400 --> 00:20:30,280 and on the other side, we have this blood-letting. 315 00:20:30,280 --> 00:20:33,520 But this was part of their cosmovision - 316 00:20:33,520 --> 00:20:35,760 it was part of their religion. 317 00:20:35,760 --> 00:20:38,200 It was part of their everyday life. 318 00:20:38,200 --> 00:20:44,120 I wonder... If sacrifice was such a big part of their culture, 319 00:20:44,120 --> 00:20:45,960 especially with children... 320 00:20:45,960 --> 00:20:48,160 But how often were they actually doing that? 321 00:20:48,160 --> 00:20:50,400 Cos I guess it would be counterproductive 322 00:20:50,400 --> 00:20:52,640 to be killing that many children. 323 00:20:52,640 --> 00:20:55,880 I'm not trying to justify anything but, you know, 324 00:20:55,880 --> 00:20:59,800 I believe that sometimes those were acts of love... 325 00:20:59,800 --> 00:21:02,360 ..to sacrifice children. 326 00:21:02,360 --> 00:21:07,440 Remember that the Maya believe in life after this life. 327 00:21:07,440 --> 00:21:11,400 They were expecting this person to either go to another place 328 00:21:11,400 --> 00:21:14,920 and carry a message, and they can bring it back... 329 00:21:14,920 --> 00:21:16,600 So we don't know exactly, 330 00:21:16,600 --> 00:21:20,040 but we do believe that most of these sacrifices 331 00:21:20,040 --> 00:21:24,120 or offerings occur in trying to please the gods, 332 00:21:24,120 --> 00:21:27,760 cos they were having problems with drought. 333 00:21:27,760 --> 00:21:29,800 When there's no rain, there's no agriculture, 334 00:21:29,800 --> 00:21:31,640 so there's no food production. 335 00:21:31,640 --> 00:21:36,480 It's like, "Please send rain to my people because we're dying." 336 00:21:37,920 --> 00:21:41,560 It's been an unsettling introduction to the world of the ancient Maya. 337 00:21:43,520 --> 00:21:45,920 And how much more is still out there? 338 00:21:45,920 --> 00:21:48,960 I believe...I believe we will find much more. 339 00:21:58,040 --> 00:22:01,880 We're on our way to another Mayan cave, one that isn't flooded. 340 00:22:03,120 --> 00:22:05,200 It's a labyrinth of dry passageways, 341 00:22:05,200 --> 00:22:09,000 thought to stretch many kilometres beneath the jungle floor. 342 00:22:10,200 --> 00:22:13,200 The cave is so vast, it's not been fully surveyed 343 00:22:13,200 --> 00:22:16,280 for the Maya secrets it may contain, 344 00:22:16,280 --> 00:22:18,960 but getting into it will be a challenge. 345 00:22:20,040 --> 00:22:21,240 With our support, 346 00:22:21,240 --> 00:22:24,440 Memo wants to explore a section of the cave comprehensively. 347 00:22:26,280 --> 00:22:30,760 We know that we have at least one, possibly two descents on ropes, 348 00:22:30,760 --> 00:22:33,920 so we're carrying as much rope as we can, 349 00:22:33,920 --> 00:22:39,120 plus all of our climbing and ascending and descending gear. 350 00:22:39,120 --> 00:22:41,720 I don't know exactly what we're going to find inside 351 00:22:41,720 --> 00:22:43,920 but, from what I understand, 352 00:22:43,920 --> 00:22:48,360 this is one of the most remarkable caves found anywhere in the planet, 353 00:22:48,360 --> 00:22:51,600 and very few people have had the privilege of going inside 354 00:22:51,600 --> 00:22:53,400 and seeing what we're about to see. 355 00:22:55,160 --> 00:22:57,840 This cave was so special to the Maya, 356 00:22:57,840 --> 00:23:00,440 they risked their lives to enter it. 357 00:23:02,440 --> 00:23:04,760 We want to see just how far they managed to get. 358 00:23:06,200 --> 00:23:07,840 It won't be easy. 359 00:23:07,840 --> 00:23:10,960 In the last few weeks, someone fell to their death here. 360 00:23:12,760 --> 00:23:14,800 We're taking every precaution. 361 00:23:16,440 --> 00:23:17,880 Just so that everyone knows, 362 00:23:17,880 --> 00:23:19,880 this is where the med kit is going to be. 363 00:23:19,880 --> 00:23:22,120 If it's me that ends up incapacitated in there, 364 00:23:22,120 --> 00:23:24,280 the med kit's here and the stretcher's here. 365 00:23:25,560 --> 00:23:30,160 Unless both you and I take a catastrophic fall, 366 00:23:30,160 --> 00:23:32,880 then we should be able to come out and... Let someone know. 367 00:23:32,880 --> 00:23:35,080 ..raise the alarm. OK. 368 00:23:38,600 --> 00:23:41,600 If you're not back by 6am, we're coming in. 369 00:23:41,600 --> 00:23:44,040 So is that 6am? Yeah. 370 00:23:44,040 --> 00:23:45,280 Yeah, that's you. 371 00:23:47,120 --> 00:23:50,440 Oh, it gets tight already. 372 00:23:50,440 --> 00:23:51,800 It is. 373 00:23:51,800 --> 00:23:53,400 Just go careful, mate. 374 00:23:53,400 --> 00:23:55,840 Here, are we just passing bags through? Yeah. 375 00:23:55,840 --> 00:23:58,480 You definitely said no more caves, Steve, a few years ago. 376 00:23:58,480 --> 00:24:00,080 I know. I did... 377 00:24:01,800 --> 00:24:03,280 Do you know what's amazing? 378 00:24:03,280 --> 00:24:07,200 Just look at all this kit we've got, and head torches and lights... 379 00:24:07,200 --> 00:24:09,640 Imagine doing it naked. 380 00:24:09,640 --> 00:24:11,280 Why would you want to do it naked? 381 00:24:11,280 --> 00:24:13,120 The way they did - 382 00:24:13,120 --> 00:24:16,040 barefooted with burning torches. 383 00:24:16,040 --> 00:24:17,560 Shout me when you're through. 384 00:24:19,760 --> 00:24:21,880 So we're only just into the cave, 385 00:24:21,880 --> 00:24:25,320 and already we've got our first drop down into the darkness. 386 00:24:25,320 --> 00:24:27,560 It's uncertain how long it is. 387 00:24:27,560 --> 00:24:29,600 How much are we sending down, Aldo? 388 00:24:29,600 --> 00:24:31,800 Throw it all down that fall line. 389 00:24:31,800 --> 00:24:35,240 See where... See right down through that cleft? 390 00:24:35,240 --> 00:24:36,280 Yeah. 391 00:24:38,400 --> 00:24:41,360 Perfect, mate. Good shot. Good shot. 392 00:24:41,360 --> 00:24:45,320 So when you're coming down, don't run the rope over an edge 393 00:24:45,320 --> 00:24:49,040 or somewhere that it could get jammed. 394 00:24:49,040 --> 00:24:50,880 It's so humid in here. 395 00:24:50,880 --> 00:24:53,520 You can see all the water droplets just floating around 396 00:24:53,520 --> 00:24:54,960 in my headlight. Hey, Steve. 397 00:24:54,960 --> 00:24:57,000 It's... Mainly, this is just for support. 398 00:24:57,000 --> 00:24:59,640 Pretty much on your feet the whole way down. 399 00:25:02,480 --> 00:25:05,320 Probably a 5m drop at the bottom. 400 00:25:05,320 --> 00:25:08,400 Is the rope enough? Plenty. 401 00:25:08,400 --> 00:25:12,560 I'm on the bottom level of the first abseil. 402 00:25:12,560 --> 00:25:15,040 Order of march, Steve. Next, who do you want down? 403 00:25:15,040 --> 00:25:17,080 I'm going to send Memo down next. 404 00:25:17,080 --> 00:25:19,040 Yeah. Clear rope! 405 00:25:29,080 --> 00:25:30,440 Are you OK, Memo? 406 00:25:32,360 --> 00:25:34,240 I'm fine, thank you. 407 00:25:34,240 --> 00:25:35,560 It's very slippery. 408 00:25:35,560 --> 00:25:37,600 Yeah, yeah. 409 00:25:37,600 --> 00:25:40,240 We're about an hour or so into the cave. 410 00:25:40,240 --> 00:25:43,480 Memo said the earliest people were using this cave 411 00:25:43,480 --> 00:25:46,360 was maybe 2,500 years ago, 412 00:25:46,360 --> 00:25:49,920 so they would have been making these descents that I'm doing now 413 00:25:49,920 --> 00:25:52,720 on completely natural fibre ropes. 414 00:25:52,720 --> 00:25:54,880 It's just incredible. 415 00:25:54,880 --> 00:25:58,600 It actually makes us with all our modern methods 416 00:25:58,600 --> 00:26:00,960 feel a little bit pathetic. 417 00:26:00,960 --> 00:26:03,400 We've got a long, long way to go. 418 00:26:09,160 --> 00:26:11,360 It is hot. 419 00:26:13,400 --> 00:26:17,840 It's taken us nearly an hour just to get the team down this 5m drop. 420 00:26:19,680 --> 00:26:25,400 If they came down to this on a rope made from natural fibres, 421 00:26:25,400 --> 00:26:27,160 how did they climb back up? 422 00:26:27,160 --> 00:26:31,720 They may have had some kind of scaffold system, 423 00:26:31,720 --> 00:26:34,480 or maybe wooden ladders, 424 00:26:34,480 --> 00:26:37,000 but we haven't seen evidence of that. 425 00:26:40,840 --> 00:26:43,920 After dropping down this challenging overhang, 426 00:26:43,920 --> 00:26:47,160 we come across our first sign of the Maya. 427 00:26:47,160 --> 00:26:48,960 Look at this, Steve. 428 00:26:48,960 --> 00:26:50,520 What have you got? 429 00:26:50,520 --> 00:26:54,760 This is a very important symbolic construction 430 00:26:54,760 --> 00:26:58,160 which represents the mountain of creation. Yeah? 431 00:26:58,160 --> 00:26:59,480 This is like a penis, 432 00:26:59,480 --> 00:27:04,560 so this is a monument to life, to fertility. 433 00:27:09,040 --> 00:27:13,480 I don't know, but maybe we're 60 or 100m below the ground? 434 00:27:13,480 --> 00:27:16,000 The Maya managed to come all the way here, 435 00:27:16,000 --> 00:27:18,320 build this fantastic altar, 436 00:27:18,320 --> 00:27:20,640 made an offering, 437 00:27:20,640 --> 00:27:25,560 and pray for rain or for harvest. 438 00:27:25,560 --> 00:27:28,320 Wow. That's incredible. It is. 439 00:27:30,160 --> 00:27:33,400 Although they referred to these caves as The Place Of Fear, 440 00:27:33,400 --> 00:27:35,960 the Maya were still drawn to them. 441 00:27:35,960 --> 00:27:40,360 As their civilisation crumbled and life became harder, 442 00:27:40,360 --> 00:27:43,520 archaeologists think they ventured into these labyrinths 443 00:27:43,520 --> 00:27:46,200 to honour the gods they held responsible. 444 00:27:48,000 --> 00:27:49,840 We're four hours in. 445 00:27:49,840 --> 00:27:52,080 We've reached a point the passageway spreads out 446 00:27:52,080 --> 00:27:56,880 like the spokes of a wheel, pointing north, south, east and west. 447 00:27:59,080 --> 00:28:02,760 So I think these caves run on all the cardinal points, bizarrely. 448 00:28:02,760 --> 00:28:05,440 Yeah. The one that we should be going down is the west. 449 00:28:05,440 --> 00:28:10,680 So that's... North is that way. And that's west. Yeah. 450 00:28:12,800 --> 00:28:15,240 Smashed pots litter the cave. 451 00:28:15,240 --> 00:28:16,680 They once held offerings, 452 00:28:16,680 --> 00:28:19,880 and the Maya are thought to have broken them intentionally 453 00:28:19,880 --> 00:28:22,600 to release the spiritual power of what was inside them. 454 00:28:23,760 --> 00:28:25,400 What's that? 455 00:28:25,400 --> 00:28:27,720 Ground stone. 456 00:28:27,720 --> 00:28:30,200 What?! That must weigh 25 kilos. 457 00:28:30,200 --> 00:28:32,920 How did they get that down a cave? 458 00:28:32,920 --> 00:28:34,840 That's amazing. 459 00:28:34,840 --> 00:28:38,200 It's kind of like a detective story, putting it all back together. 460 00:28:39,800 --> 00:28:41,440 What have you got, Guillermo? 461 00:28:41,440 --> 00:28:42,680 It's right here. 462 00:28:42,680 --> 00:28:46,720 It's a beautiful, beautiful ceramic pot. 463 00:28:46,720 --> 00:28:49,800 First time I've seen something like this. You've never seen this before? 464 00:28:49,800 --> 00:28:55,320 No, and probably it's thousands of years that had been there. 465 00:28:55,320 --> 00:28:57,880 It's perfect. It's even sculpted. 466 00:28:57,880 --> 00:29:00,520 It's perfect. It's beautiful. It's unusual. 467 00:29:00,520 --> 00:29:02,360 How on earth did they get in there? 468 00:29:02,360 --> 00:29:05,000 They place it there - they hide it. 469 00:29:05,000 --> 00:29:07,640 The ancient Maya sometimes do that. Whoa... 470 00:29:07,640 --> 00:29:09,880 ..and we can't even get it out. 471 00:29:09,880 --> 00:29:12,880 Yeah. No. No way. 472 00:29:12,880 --> 00:29:15,280 Yeah. It's stuck there. It's stuck, yeah. 473 00:29:17,440 --> 00:29:20,440 There are discoveries around every corner here. Yes, of course. 474 00:29:20,440 --> 00:29:23,000 Of course. We could spend months inside this cave 475 00:29:23,000 --> 00:29:24,520 and keep discovering things. 476 00:29:26,000 --> 00:29:27,120 It's so cool. 477 00:29:37,440 --> 00:29:38,720 Isn't that amazing? 478 00:29:38,720 --> 00:29:39,960 Whoa. 479 00:29:50,280 --> 00:29:52,320 Oh! Oh... Oh, wow! 480 00:29:52,320 --> 00:29:53,960 Look at that! 481 00:29:53,960 --> 00:29:57,000 That is one of the most amazing things. 482 00:29:57,000 --> 00:29:59,640 Look at it - it's completely three-dimensional. 483 00:30:01,800 --> 00:30:03,120 Amazing. 484 00:30:05,120 --> 00:30:07,360 Well, it's definitely a mammal, isn't it? 100%. 485 00:30:07,360 --> 00:30:12,120 What were the important mammals to them thousands of years ago? 486 00:30:12,120 --> 00:30:15,400 Tapir? Pig, perhaps? Could be a peccary. 487 00:30:15,400 --> 00:30:18,080 It's so cool that they've taken this chunk of rock, 488 00:30:18,080 --> 00:30:21,920 this part of the cave, and they've used its natural features 489 00:30:21,920 --> 00:30:24,240 to form the head of the animal, and the body as well. 490 00:30:24,240 --> 00:30:27,160 You can see it almost looks like it's leaping out the wall. 491 00:30:27,160 --> 00:30:28,760 There's a parrot. 492 00:30:28,760 --> 00:30:30,320 Look at that. That's amazing. 493 00:30:30,320 --> 00:30:33,840 The face... That's so... It looks like it was done by a graffiti... 494 00:30:33,840 --> 00:30:36,000 It looks like it was done by Banksy. Banksy. 495 00:30:36,000 --> 00:30:37,520 THEY LAUGH 496 00:30:37,520 --> 00:30:38,760 That's so good. 497 00:30:38,760 --> 00:30:40,880 Imagine how far in we are at the minute. 498 00:30:40,880 --> 00:30:42,320 How long have we been going for? 499 00:30:42,320 --> 00:30:45,400 Erm, six hours at this point. 500 00:30:45,400 --> 00:30:46,600 Six hours. 501 00:30:46,600 --> 00:30:50,120 So they came six hours into a cave and created works of art. 502 00:30:52,720 --> 00:30:56,720 The Maya believed some animals had the power to enter the underworld, 503 00:30:56,720 --> 00:30:59,360 and they celebrated them in paintings like these. 504 00:31:03,440 --> 00:31:05,360 Look at this, Steve. 505 00:31:07,840 --> 00:31:10,160 It's a jaguar. It's a jaguar, yes. 506 00:31:10,160 --> 00:31:12,760 I see it. Look at the face. It's looking back over its shoulder. 507 00:31:12,760 --> 00:31:14,440 Look at the eyes. It's amazing. 508 00:31:14,440 --> 00:31:17,040 It's really amazing, the motion. And I see the spots. 509 00:31:17,040 --> 00:31:20,480 And look at the tail. That's definitely a jaguar tail... 510 00:31:20,480 --> 00:31:23,520 That's amazing. ..which makes it different than the puma or cougar. 511 00:31:23,520 --> 00:31:26,360 Yeah. It's really a jaguar. 512 00:31:26,360 --> 00:31:27,800 It's beautiful. 513 00:31:29,800 --> 00:31:33,920 Many of the oldest Maya deities took the form of an animal, 514 00:31:33,920 --> 00:31:36,760 and this was the jaguar god of the underworld 515 00:31:36,760 --> 00:31:39,160 known as the Night Sun. 516 00:31:41,160 --> 00:31:43,120 The animal in front of it, what's that? 517 00:31:43,120 --> 00:31:45,680 It really looks like a deer. 518 00:31:45,680 --> 00:31:49,360 These two animals were able to go into the underworld 519 00:31:49,360 --> 00:31:51,360 where we are right now... Yeah. 520 00:31:51,360 --> 00:31:54,520 ..and be able to survive and go back. 521 00:31:54,520 --> 00:31:57,560 This painting represents one of the most revered 522 00:31:57,560 --> 00:31:59,200 and powerful Maya gods. 523 00:32:00,520 --> 00:32:04,160 The artists overcame extreme dangers to paint it here 524 00:32:04,160 --> 00:32:07,640 in the deepest part of this section of the cave. 525 00:32:09,640 --> 00:32:11,720 Nothing here is done by accident, is it? 526 00:32:11,720 --> 00:32:15,800 Yeah, definitely nothing. Anything that's done this far into the cave, 527 00:32:15,800 --> 00:32:19,520 that's taken this much sweat and effort. Yes, all this effort... 528 00:32:19,520 --> 00:32:22,640 It's quite something to think of someone 529 00:32:22,640 --> 00:32:25,680 standing barefoot where we are right now, 530 00:32:25,680 --> 00:32:28,320 with a blazing torch to light them, 531 00:32:28,320 --> 00:32:31,600 and painting, with charcoal, this drawing onto the wall 532 00:32:31,600 --> 00:32:34,800 and leaving it here, and now we're sat here trying to decipher it, 533 00:32:34,800 --> 00:32:36,680 trying to find its meaning. 534 00:32:36,680 --> 00:32:38,040 It gives me goose bumps. 535 00:32:47,840 --> 00:32:53,960 We are in the sanctum sanctorum of religion of the ancient Maya, 536 00:32:53,960 --> 00:32:55,960 the centre of the Earth - 537 00:32:55,960 --> 00:32:57,200 the underworld. 538 00:33:02,040 --> 00:33:06,320 Memo has given us a glimpse into the incredible world of the Maya. 539 00:33:06,320 --> 00:33:09,360 Their beliefs were so powerful that they risked it all 540 00:33:09,360 --> 00:33:12,520 to reach these subterranean places of worship. 541 00:33:15,240 --> 00:33:17,640 Everything about this place, 542 00:33:17,640 --> 00:33:22,560 I just feel like I've been connected back through time 543 00:33:22,560 --> 00:33:26,320 2,000 years to the people that used to walk through here. It's... 544 00:33:26,320 --> 00:33:29,480 It's hard not to feel like that. Yeah. 545 00:33:29,480 --> 00:33:32,120 It's time to say goodbye and move on, 546 00:33:32,120 --> 00:33:34,760 but Memo's work in this cave will continue. 547 00:33:37,160 --> 00:33:38,920 Thank you, Guillermo. No, thank you. 548 00:33:38,920 --> 00:33:41,880 It was really a privilege to share with you and your friends. 549 00:33:41,880 --> 00:33:45,320 And not many people have seen it, well, since the ancient Maya times. 550 00:33:45,320 --> 00:33:48,960 Exactly, exactly, thousands of years ago. 551 00:33:56,000 --> 00:33:59,280 The Maya didn't only worship the gods of the underworld - 552 00:33:59,280 --> 00:34:01,560 they built pyramids to the glory of the gods 553 00:34:01,560 --> 00:34:03,400 that existed in the heavens, too. 554 00:34:08,440 --> 00:34:12,520 Yucatan is incredibly flat, 555 00:34:12,520 --> 00:34:16,200 so any time you find a hill, 556 00:34:16,200 --> 00:34:18,640 it's not going to be natural. It's artificial. 557 00:34:18,640 --> 00:34:21,920 These blocks have been put here by the ancient Maya 558 00:34:21,920 --> 00:34:25,320 and would once have been pyramids like that one there. 559 00:34:29,400 --> 00:34:34,200 Over time they've crumbled, and become part of the dense jungle 560 00:34:34,200 --> 00:34:36,120 and home for its wildlife. 561 00:34:41,000 --> 00:34:45,840 These limestone blocks from the ruins are perfect 562 00:34:45,840 --> 00:34:47,480 for animals to hide out in, 563 00:34:47,480 --> 00:34:52,160 and this has obviously been the home of a pretty substantial snake. 564 00:34:52,160 --> 00:34:54,520 That's its shed skin, 565 00:34:54,520 --> 00:34:59,480 and the live animal must be at least 2m long. 566 00:35:07,320 --> 00:35:10,920 No... Look at that. 567 00:35:10,920 --> 00:35:12,280 HE GASPS 568 00:35:12,280 --> 00:35:18,560 I'm watching one of the most macabre sights in nature right now. 569 00:35:18,560 --> 00:35:22,400 This is the world's largest species of wasp, the tarantula hawk wasp, 570 00:35:22,400 --> 00:35:24,880 which is as long as my thumb, 571 00:35:24,880 --> 00:35:30,920 and it has a hold of a fully-grown Mexican red rump tarantula. 572 00:35:30,920 --> 00:35:33,800 The spider, though, is not any longer putting up a fight 573 00:35:33,800 --> 00:35:35,200 because it's been paralysed. 574 00:35:35,200 --> 00:35:37,240 But this is not going to be her meal. 575 00:35:37,240 --> 00:35:39,720 This is a meal for her young. 576 00:35:39,720 --> 00:35:42,000 Here she goes, she's going to grab it again, 577 00:35:42,000 --> 00:35:44,400 so she'll grab it in her jaws 578 00:35:44,400 --> 00:35:48,000 and then start dragging it to her burrow. 579 00:35:48,000 --> 00:35:49,480 Once she's got it there, 580 00:35:49,480 --> 00:35:53,000 she'll lay one single egg onto the abdomen of the spider, 581 00:35:53,000 --> 00:35:56,240 and that will hatch out and eat it from the inside out, 582 00:35:56,240 --> 00:35:59,320 eating around the vital organs so the meat stays fresh 583 00:35:59,320 --> 00:36:01,200 for as long as possible. 584 00:36:01,200 --> 00:36:04,920 It's absolutely hideous. So macabre. 585 00:36:04,920 --> 00:36:07,760 The Maya would have watched things like this 586 00:36:07,760 --> 00:36:11,160 and had significance for it, because how could you not? 587 00:36:14,640 --> 00:36:17,280 The wild world can be cruel, 588 00:36:17,280 --> 00:36:20,000 and the Maya did gruesome things themselves 589 00:36:20,000 --> 00:36:22,120 to stave off nature's cruelty. 590 00:36:24,360 --> 00:36:25,920 It didn't help them. 591 00:36:25,920 --> 00:36:28,640 Famine, drought and other natural disasters 592 00:36:28,640 --> 00:36:33,520 could well have caused the collapse of the cities of the ancient Maya. 593 00:36:43,880 --> 00:36:47,720 We're back exploring the caves under the Yucatan, 594 00:36:47,720 --> 00:36:49,760 and my colleague Robbie Schmittner 595 00:36:49,760 --> 00:36:52,000 now thinks he may have found the perfect place. 596 00:36:56,480 --> 00:36:59,320 He's been mapping underwater caves in the region for years, 597 00:36:59,320 --> 00:37:02,200 to help scientists protect the fresh water there 598 00:37:02,200 --> 00:37:04,600 from the growing threat of pollution. 599 00:37:05,840 --> 00:37:08,440 His search has identified a cave in the forest 600 00:37:08,440 --> 00:37:10,920 that's thought to have Maya artefacts. 601 00:37:13,840 --> 00:37:17,520 A lot of exploration is about following stories and legends. 602 00:37:17,520 --> 00:37:20,960 So, we have a lead that there is a cave in the forest. 603 00:37:20,960 --> 00:37:22,080 You never know - 604 00:37:22,080 --> 00:37:24,000 I mean, it could turn into nothing at all - 605 00:37:24,000 --> 00:37:26,520 but it's still super, super exciting. 606 00:37:28,960 --> 00:37:33,240 The entrance has been explored, but not its furthest reaches. 607 00:37:33,240 --> 00:37:34,960 We want to see what's in there, 608 00:37:34,960 --> 00:37:39,280 and find out how far the ancient Maya journeyed into the cave. 609 00:37:39,280 --> 00:37:43,000 Oh, cool. That's a proper cave. 610 00:37:43,000 --> 00:37:47,040 It's a decent-sized entrance, isn't it? It's massive. 611 00:37:47,040 --> 00:37:52,320 A few metres in and we come across our first signs of the Maya. 612 00:37:52,320 --> 00:37:53,560 Check this out, Steve. 613 00:37:53,560 --> 00:37:55,840 Whoa. That's an old altar. 614 00:37:57,280 --> 00:37:58,800 That's amazing. 615 00:37:58,800 --> 00:37:59,840 Look at that. 616 00:38:02,480 --> 00:38:04,520 Wow. That's really cool. 617 00:38:04,520 --> 00:38:07,560 And it has stucco, plaster all over it. 618 00:38:07,560 --> 00:38:11,200 Lime plaster like this was used by the Maya from 600 BC. 619 00:38:12,920 --> 00:38:14,800 When it was used on buildings outside, 620 00:38:14,800 --> 00:38:16,920 it often didn't survive the weather, 621 00:38:16,920 --> 00:38:19,320 but in here, it's been protected. 622 00:38:24,600 --> 00:38:26,040 Look at that. 623 00:38:26,040 --> 00:38:28,880 It's like a face, like a smiley face. Yeah. 624 00:38:28,880 --> 00:38:32,240 That stalactite, that doesn't look like it's been placed there, 625 00:38:32,240 --> 00:38:35,640 I think the altar's been built around it. 626 00:38:35,640 --> 00:38:37,000 ALDO BLOWS RASPBERRIES 627 00:38:37,000 --> 00:38:38,160 Mind blown. 628 00:38:38,160 --> 00:38:42,920 Yeah. This is exactly what Memo was talking about. Look at this. 629 00:38:42,920 --> 00:38:44,920 This is THE most sacred thing. 630 00:38:44,920 --> 00:38:46,160 A stalagmite coming up - 631 00:38:46,160 --> 00:38:49,400 that represents the phallus, that represents the male - 632 00:38:49,400 --> 00:38:51,440 and this coming down, 633 00:38:51,440 --> 00:38:54,480 the stalactite, which represents the female. 634 00:38:54,480 --> 00:38:57,120 This is probably why that altar is right there, 635 00:38:57,120 --> 00:39:00,200 because that is just screaming out 636 00:39:00,200 --> 00:39:03,280 for everything from Mayan iconography and symbolism. 637 00:39:08,920 --> 00:39:11,120 It looks like it could have been, perhaps, 638 00:39:11,120 --> 00:39:13,560 something for carrying water in. Yeah. 639 00:39:16,520 --> 00:39:19,880 What is it? Pottery? Yeah! Yeah, it's a bit of ceramic. 640 00:39:19,880 --> 00:39:23,120 We didn't see anything like that in that other cave. 641 00:39:23,120 --> 00:39:27,200 I've never seen anything like in the shape of that. 642 00:39:27,200 --> 00:39:29,880 That's completely...unique. 643 00:39:29,880 --> 00:39:32,760 I think you might have found something quite special here, Robbie. 644 00:39:32,760 --> 00:39:35,640 It's a special place, definitely. 645 00:39:38,560 --> 00:39:40,920 We're going to leave the daylight zone here right now. 646 00:39:40,920 --> 00:39:42,760 We need a bit more light. 647 00:39:46,560 --> 00:39:49,720 We're going to push on as far as we can into the cave, 648 00:39:49,720 --> 00:39:52,560 going deeper than anyone has explored before. 649 00:39:55,920 --> 00:39:58,200 It's not just stalactites coming down into the cave - 650 00:39:58,200 --> 00:40:02,920 there are twisted tree roots dropping down, searching for water. 651 00:40:02,920 --> 00:40:07,240 And right there...is a whip spider. 652 00:40:10,560 --> 00:40:12,440 Very creepy-looking critters. 653 00:40:14,320 --> 00:40:16,920 That's absolutely stunning. 654 00:40:16,920 --> 00:40:18,440 It taps around in the darkness, 655 00:40:18,440 --> 00:40:21,960 with these extended legs which function almost like antennae. 656 00:40:21,960 --> 00:40:23,640 That's how it finds its prey. 657 00:40:39,080 --> 00:40:41,000 It is genuinely quite worrying 658 00:40:41,000 --> 00:40:43,320 when you think about how big this cavern is, 659 00:40:43,320 --> 00:40:44,800 how much weight is above it, 660 00:40:44,800 --> 00:40:47,400 and how little support there seems to be on the inside. 661 00:40:52,720 --> 00:40:56,720 We're now hundreds of metres from the surface. 662 00:40:56,720 --> 00:40:59,200 There are no human artefacts this far in, 663 00:40:59,200 --> 00:41:03,480 but there are rock formations and they're staggeringly beautiful. 664 00:41:07,600 --> 00:41:11,480 This is probably the most decorated cave system I've ever been in. 665 00:41:11,480 --> 00:41:12,800 Everywhere you look, 666 00:41:12,800 --> 00:41:15,840 there's something unique and new and fragile. 667 00:41:16,880 --> 00:41:18,120 And in this corner, 668 00:41:18,120 --> 00:41:21,680 there are thousands of what are called helictites. 669 00:41:21,680 --> 00:41:24,840 It's where the stalactite seems to go completely crazy 670 00:41:24,840 --> 00:41:27,440 and starts growing off in the wrong directions. 671 00:41:27,440 --> 00:41:29,560 It's growing upwards, it's growing sideways, 672 00:41:29,560 --> 00:41:31,680 sticking out all over the place, 673 00:41:31,680 --> 00:41:35,040 and it's still a bit of a mystery why this happens. 674 00:41:35,040 --> 00:41:38,400 The original idea was that it was due to wind movement, 675 00:41:38,400 --> 00:41:42,080 that the air would start the calcite forming in different directions, 676 00:41:42,080 --> 00:41:45,000 but I don't know, that seems a little bit far-fetched. 677 00:41:45,000 --> 00:41:48,760 Another suggestion is it could be down to growth of bacteria 678 00:41:48,760 --> 00:41:52,200 which just start going off in all kinds of crazy directions, whatever. 679 00:41:52,200 --> 00:41:56,680 All of a sudden, it transforms these wonderful hanging structures 680 00:41:56,680 --> 00:41:59,520 into something far more complex, 681 00:41:59,520 --> 00:42:02,360 and every single one of them is different and unique, 682 00:42:02,360 --> 00:42:04,200 and just a little sound... 683 00:42:04,200 --> 00:42:12,120 PERCUSSIVE NOTES CHIME 684 00:42:12,120 --> 00:42:14,200 ..like a subterranean xylophone. 685 00:42:15,800 --> 00:42:17,280 We're deep inside the cave, 686 00:42:17,280 --> 00:42:20,440 and there's no evidence the Maya made it this far, 687 00:42:20,440 --> 00:42:23,680 but something else catches our eye. 688 00:42:23,680 --> 00:42:25,520 Whoa. 689 00:42:25,520 --> 00:42:27,640 It's a lake. 690 00:42:27,640 --> 00:42:29,120 Yeah. 691 00:42:29,120 --> 00:42:31,920 A complete underground lake. Crystal clear. 692 00:42:36,480 --> 00:42:39,120 It's a thrilling discovery. 693 00:42:39,120 --> 00:42:40,760 This is what Robbie lives for. 694 00:42:48,640 --> 00:42:53,560 I think we should get the scuba gear here and get in there and dive it. 695 00:42:56,040 --> 00:42:59,320 Back there it looks all dark, even with the light. 696 00:42:59,320 --> 00:43:01,480 That's where I would start searching first. 697 00:43:03,720 --> 00:43:07,320 The dark shadow marks the start of a water-filled cavern 698 00:43:07,320 --> 00:43:09,440 that will either lead to a dead end 699 00:43:09,440 --> 00:43:12,240 or continue on for countless kilometres. 700 00:43:15,440 --> 00:43:18,160 We decide to make camp at the cave entrance, 701 00:43:18,160 --> 00:43:20,000 and prepare to dive in the morning. 702 00:43:26,280 --> 00:43:28,360 Cave diving is often described 703 00:43:28,360 --> 00:43:31,560 as one of the most dangerous types of exploration. 704 00:43:35,760 --> 00:43:39,080 This will be one of the hardest dives I've ever done, 705 00:43:39,080 --> 00:43:42,120 and our lives will depend on a single line. 706 00:43:43,560 --> 00:43:46,560 I do need to prepare that guideline, 707 00:43:46,560 --> 00:43:48,840 because when we measure the cave, 708 00:43:48,840 --> 00:43:52,920 placing that guideline is our lifeline to come back out, 709 00:43:52,920 --> 00:43:58,680 but it's also the line which we need to survey and make the cave map. 710 00:43:58,680 --> 00:44:02,960 You can't get line knotted at the market...supermarket already. 711 00:44:02,960 --> 00:44:06,280 We have to do that all the time before we go diving. 712 00:44:07,840 --> 00:44:10,960 From Robbie's experience of the geology in this area, 713 00:44:10,960 --> 00:44:13,760 we're expecting to encounter tight squeezes - 714 00:44:13,760 --> 00:44:17,440 passageways barely big enough to get our bodies through. 715 00:44:19,080 --> 00:44:22,960 This will push me to the limit of my diving abilities. 716 00:44:25,800 --> 00:44:30,680 As far as my job is concerned of being in charge of safety, 717 00:44:30,680 --> 00:44:32,480 generally speaking, on this expedition, 718 00:44:32,480 --> 00:44:36,160 there is nothing, absolutely nothing I can do. 719 00:44:36,160 --> 00:44:40,600 As soon as they leave the surface, they pretty much are on their own. 720 00:44:40,600 --> 00:44:42,040 There is no rescue in there. 721 00:44:43,960 --> 00:44:48,000 And the worst-case scenario is...it's body recovery. 722 00:44:48,000 --> 00:44:49,760 There is no half measures, really. 723 00:44:49,760 --> 00:44:51,960 Yeah, it's pretty...pretty scary. 724 00:44:51,960 --> 00:44:55,160 We don't know if it's a very easy dive, what we're going to do. 725 00:44:55,160 --> 00:44:57,880 We don't know what we'll find. It's exploration, right? 726 00:44:57,880 --> 00:45:01,240 My main concern is that if I die tomorrow, 727 00:45:01,240 --> 00:45:05,120 my last meal will have been a Pot Noodle. 728 00:45:05,120 --> 00:45:06,920 Nobody's going to die tomorrow. 729 00:45:06,920 --> 00:45:09,680 Cheers to that. Cheers to the dive. Cheers. 730 00:45:09,680 --> 00:45:10,880 Cheers to that - 731 00:45:10,880 --> 00:45:13,360 safe dive, safe journey and safe return. 732 00:45:22,960 --> 00:45:25,280 Goodnight, everyone. Sleep good. 733 00:45:25,280 --> 00:45:27,280 Night-night. Night, dude. 734 00:45:33,640 --> 00:45:40,320 So, one side is the jungle and the other is the cave, 735 00:45:40,320 --> 00:45:42,160 and somewhere deep in there... 736 00:45:43,720 --> 00:45:47,240 ..is probably the thing I'm most frightened of in the whole world. 737 00:45:47,240 --> 00:45:52,720 Never been much good at...little narrow spaces and squeezes. 738 00:46:00,240 --> 00:46:02,680 Get us coffee, Aldo. Hmm... 739 00:46:02,680 --> 00:46:04,520 How did you sleep? 740 00:46:04,520 --> 00:46:06,640 Yeah, very well. 741 00:46:06,640 --> 00:46:08,960 I sleep better in a hammock than I do in a bed. 742 00:46:14,960 --> 00:46:17,720 I love living like a caveman. 743 00:46:17,720 --> 00:46:19,920 The simplicity of life... 744 00:46:19,920 --> 00:46:22,520 Get up, start fire, have coffee. 745 00:46:22,520 --> 00:46:24,600 I don't know if cavemen had coffee. 746 00:46:24,600 --> 00:46:28,200 What?! OK, I don't want to be a caveman any more. Nah. 747 00:46:31,320 --> 00:46:33,520 Robbie, do you want coffee? Sure. 748 00:46:33,520 --> 00:46:35,200 How do you take it? 749 00:46:35,200 --> 00:46:36,200 Milk, please. 750 00:46:39,840 --> 00:46:41,880 Dive plan for this morning, Robbie? 751 00:46:41,880 --> 00:46:46,080 Our main danger always, always in cave-diving is our own mind. 752 00:46:46,080 --> 00:46:50,440 The most important thing is stay calm at all times. 753 00:46:52,400 --> 00:46:55,040 We cannot panic. It's impossible. Not... 754 00:46:56,920 --> 00:46:59,360 Not an option, right? 755 00:47:18,040 --> 00:47:21,440 This is subtly different, what we're doing this time. 756 00:47:21,440 --> 00:47:23,520 We're going for a slightly different system. 757 00:47:23,520 --> 00:47:28,200 I'm not using the full facemask that allows me to talk underwater. 758 00:47:28,200 --> 00:47:31,960 Instead, I'm going for a more conventional cave diving set-up, 759 00:47:31,960 --> 00:47:34,680 which should be safer, more manoeuvrable 760 00:47:34,680 --> 00:47:36,320 and help me to get to places 761 00:47:36,320 --> 00:47:39,160 that I just wouldn't be able to with the big mask. 762 00:47:40,680 --> 00:47:42,600 I'll go in front with the reel. 763 00:47:42,600 --> 00:47:45,200 You know, stay close by the guideline - 764 00:47:45,200 --> 00:47:47,280 always in reach distance. 765 00:47:47,280 --> 00:47:50,840 If anything goes wrong, if anything is not ideal, 766 00:47:50,840 --> 00:47:52,880 let's just call it and go back. 767 00:47:52,880 --> 00:47:55,000 All right, sounds good. 768 00:47:55,000 --> 00:47:56,920 All right. Let's do it. 769 00:48:07,120 --> 00:48:09,000 1400 hours. 770 00:48:09,000 --> 00:48:10,440 OK. 771 00:48:10,440 --> 00:48:13,480 All right. Waiting on you, Robbie. All right, let's do this. 772 00:48:48,040 --> 00:48:51,680 We're the first people ever to see these stalactites... 773 00:48:56,080 --> 00:49:00,000 ..and set our eyes on this. 774 00:49:10,560 --> 00:49:15,240 This is an optical illusion caused when a shallow pocket of air 775 00:49:15,240 --> 00:49:18,080 is trapped against the roof of the cave. 776 00:49:24,400 --> 00:49:29,680 I don't know if the air in here is breathable. 777 00:49:29,680 --> 00:49:31,040 It probably, actually, 778 00:49:31,040 --> 00:49:35,640 from the fact my breathing is almost instantly going up quite a lot... 779 00:49:35,640 --> 00:49:38,400 ..probably means that there's not a lot of oxygen in here 780 00:49:38,400 --> 00:49:40,080 and it's mostly carbon dioxide. 781 00:49:42,040 --> 00:49:46,120 Oh, yeah. The air in here is not good. Definitely not. 782 00:49:46,120 --> 00:49:48,880 HE BREATHES IN FROM OXYGEN CANISTER 783 00:49:48,880 --> 00:49:54,200 There's always that slight sense of panic 784 00:49:54,200 --> 00:49:57,920 as his heart rate starts going up, and your breathing starts going up, 785 00:49:57,920 --> 00:50:00,240 because there's just not enough oxygen. 786 00:50:00,240 --> 00:50:02,800 HE BREATHES IN FROM OXYGEN CANISTER 787 00:50:02,800 --> 00:50:08,440 Robbie has just dropped down into a little crack and he's disappeared, 788 00:50:08,440 --> 00:50:10,400 and he's gone completely, 789 00:50:10,400 --> 00:50:12,120 which is pretty nerve-racking, 790 00:50:12,120 --> 00:50:14,800 because it means that I'll have to follow. 791 00:50:16,680 --> 00:50:20,040 But this little bell here, 792 00:50:20,040 --> 00:50:21,880 nobody's ever been here before. 793 00:50:23,240 --> 00:50:25,320 And where Robbie's gone now, 794 00:50:25,320 --> 00:50:28,160 I'm not sure anyone should ever go, really. 795 00:50:35,320 --> 00:50:39,600 Here, the cave drops down into a tight squeeze - 796 00:50:39,600 --> 00:50:41,760 the smallest I've attempted. 797 00:50:58,920 --> 00:51:01,680 HE SCREAMS 798 00:51:01,680 --> 00:51:05,040 I can't move forward or backward. 799 00:51:05,040 --> 00:51:06,360 I'm stuck. 800 00:51:08,920 --> 00:51:14,560 HE SCREAMS 801 00:51:16,720 --> 00:51:21,760 I force myself to slow down, calm down and think about my breathing. 802 00:51:29,600 --> 00:51:32,440 I exhale, and the cave lets me go. 803 00:51:38,200 --> 00:51:41,480 Robbie's waiting on the other side in a clear tunnel. 804 00:51:45,200 --> 00:51:49,480 My only comfort is that I'm with one of the world's top cave divers. 805 00:51:52,480 --> 00:51:55,760 He stays alive because he dives within his ability. 806 00:51:58,160 --> 00:51:59,840 If he reaches his limit, 807 00:51:59,840 --> 00:52:03,320 he always turns back and lives to dive another day. 808 00:52:07,240 --> 00:52:10,560 We're approaching a second squeeze and I'm nervous. 809 00:52:20,080 --> 00:52:23,480 This one is technically more difficult than the last, 810 00:52:23,480 --> 00:52:25,360 but I'm determined to try. 811 00:52:46,120 --> 00:52:48,120 Something on my harness is caught. 812 00:53:17,120 --> 00:53:19,240 I'm through to the other side, 813 00:53:19,240 --> 00:53:23,080 but now further away from safety than I've ever been. 814 00:53:26,960 --> 00:53:31,320 Beyond here, I can see another squeeze and it's smaller still. 815 00:53:43,360 --> 00:53:48,040 I don't think there's any way I can physically get through there. 816 00:53:55,160 --> 00:53:58,000 This could be the decision of my life. 817 00:54:06,040 --> 00:54:10,280 Robbie will continue on mapping, while I turn back to safety. 818 00:54:19,320 --> 00:54:22,760 Wow. Wow. 819 00:54:22,760 --> 00:54:23,880 Oh... 820 00:54:27,840 --> 00:54:29,280 What an experience. 821 00:54:36,200 --> 00:54:40,440 But we all want to know how much further Robbie managed to go. 822 00:54:42,080 --> 00:54:43,880 You ran out of line? 823 00:54:45,920 --> 00:54:47,320 What happened, man? 824 00:54:49,000 --> 00:54:51,240 It keeps going and going. It does? 825 00:54:51,240 --> 00:54:54,440 Yeah, you've got to see on here. It got really tight. 826 00:54:56,280 --> 00:54:58,320 Watching Robbie's helmet cam footage 827 00:54:58,320 --> 00:55:02,600 shows exactly what he had to go through to put all of his line out. 828 00:55:04,840 --> 00:55:06,680 He reaches a squeeze so small, 829 00:55:06,680 --> 00:55:11,120 he has to carry out the most complex manoeuvre in cave diving. 830 00:55:11,120 --> 00:55:15,000 He removes both his air cylinders, passing them one by one 831 00:55:15,000 --> 00:55:18,520 through the tiny restriction into the darkness below, 832 00:55:18,520 --> 00:55:22,240 connected only by a length of hose and his mouthpiece. 833 00:55:27,720 --> 00:55:32,920 His reward is a seemingly endless passageway on the other side. 834 00:55:46,680 --> 00:55:48,880 I just pushed on and on and at one point it was, 835 00:55:48,880 --> 00:55:50,920 "Oops, no more line." 836 00:55:50,920 --> 00:55:52,760 And the cave keeps going. 837 00:55:52,760 --> 00:55:54,440 To carry on without line 838 00:55:54,440 --> 00:55:59,040 would be breaking the golden rule of underwater cave exploration. 839 00:56:01,720 --> 00:56:03,760 How much line do you have on here? 840 00:56:03,760 --> 00:56:06,400 It's about 500m. Half a kilometre?! 841 00:56:06,400 --> 00:56:09,640 Half a kilometre. We've gone half a kilometre into the cave... 842 00:56:09,640 --> 00:56:12,480 ..and that's nothing, it hasn't even... Wow. 843 00:56:12,480 --> 00:56:15,520 It keeps going. Wow. 844 00:56:15,520 --> 00:56:17,920 That's amazing news. 845 00:56:17,920 --> 00:56:22,840 Everything I'd done up to that point was the maximum that I'm capable of. 846 00:56:22,840 --> 00:56:27,080 Being given the honour of being taken into that place, 847 00:56:27,080 --> 00:56:30,960 it's Robbie's incredible experience and knowledge 848 00:56:30,960 --> 00:56:36,240 that's allowed that to happen, and for that I owe him big time. 849 00:56:38,880 --> 00:56:41,520 It's been an incredible journey. 850 00:56:41,520 --> 00:56:43,960 The information being gathered by scientists 851 00:56:43,960 --> 00:56:46,400 will help prevent further pollution 852 00:56:46,400 --> 00:56:48,640 of these vast and interconnected waterways. 853 00:56:50,480 --> 00:56:52,520 During our six-week expedition, 854 00:56:52,520 --> 00:56:55,320 we've explored and mapped deep underground, 855 00:56:55,320 --> 00:56:58,080 adding to the growing knowledge of both the Maya 856 00:56:58,080 --> 00:57:00,640 and the area's precious water resource. 857 00:57:04,880 --> 00:57:08,920 The thing that sets us apart as a species, as human beings, 858 00:57:08,920 --> 00:57:12,800 is our desire to explore, to discover, to solve puzzles, 859 00:57:12,800 --> 00:57:15,640 and to expand the limits of human knowledge. 860 00:57:18,280 --> 00:57:22,360 Something led to the downfall of the ancient Maya. 861 00:57:22,360 --> 00:57:27,280 One theory is that overdevelopment caused an environmental crisis 862 00:57:27,280 --> 00:57:30,080 which saw them run out of fresh water. 863 00:57:35,960 --> 00:57:40,040 In Yucatan today, there's another freshwater crisis 864 00:57:40,040 --> 00:57:44,680 through pollution caused by over development. 865 00:57:44,680 --> 00:57:47,440 Surely, we should be learning the lessons.