Jungles comprise the most diverse habitats on Earth in which only the most resilient species triumph; the fiercest jungle species include jaguars, caimans, gibbons, orangutans, spectral tarsiers, hummingbirds, and parasites.
The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.
Slip through millennia-old caves in the Yucatan Peninsula of Mexico. These spooky, labyrinth-like places were considered magical as early as the Mayan era. Plus you can hitch a ride with sucker fish, dodge gigantic ocean devil fish and be entranced by the dance of a majestic 6-metre long manta ray.
Dr Helen Czerski peers into the heart of the storm to find out how advances in technology are giving new insight into tornadoes - the fastest winds on the planet. From the breathtaking footage that capture the extreme weather events that produce them, to the latest experiments investigating their incredible destructive power, Helen discovers how understanding the subtle changes deep within the storm are improving predictions of when and where these devastating beasts will strike.
Todd trains hard to improve his body intelligence, visualization skills, and emotional intelligence before attempting a super-human feat. He faces his greatest fear - being chained, handcuffed and blindfolded underwater with only his radically improved brain to help him escape.
With every step towards the summit of the mighty Drakensberg, new species of exotic animals showcase the attributes that enable them to endure their harsh mountain home. Meet the sungazer, the intriguingly named suicide lizard, and other reptiles that inhabit South Africa's high-altitude terrain.