As the Ganges nears the sea, it joins its mightiest tributary the Brahmaputra, creating a vast flood-prone delta. Here the bustling cities of Calcutta and Dhaka meet the wetlands, home to giant lizards and snakes, huge mean-eating crocodiles and forests full of monkeys. This is a story of human life persisting in wildly variable conditions in a domain that is still the preserve of the royal Bengal tiger.
David Attenborough returns in this landmark series to his most magical place on earth exploring the Great Barrier Reef aboard the research vessel Alucia. Part 1: Builders David descends beneath the waves at night in the state-of-the-art Triton submersible, the first of its kind to visit the reef. He meets some of the tiny coral animals that built the reef and helped to turn it into an underwater wonderland. He then takes to the skies to witness the vast scale of their endeavour, a living structure that provides a home for thousands of species. Using cutting-edge technology to generate computer scans of the sea floor, David learns that the Great Barrier Reef we know today is much younger than scientists ever imagined. He meets some of the people that have lived alongside it and who have told stories of its origins for thousands of years.
In the culmination of this 1,000km scientific expedition aboard the Alucia, Liz Bonnin and the team of scientific experts journey south to visit the oldest islands in the Galapagos to see first-hand the impact that humans have had on this pristine wilderness. Back on the larger island of Isabela, where her journey first began, Liz descends into a spectacular vertical lava cave. Deep inside, she discovers how this hidden world could even provide an answer to how it might be possible to inhabit other planets. On her last land-based stop, on Santa Cruz, Liz comes face to face with the effects of man as she explores the magical misty scalesia forests and meets scientists who are tracking the invasive species spreading throughout the islands. It is here that she also checks in on a giant tortoise population whose ancient migration pathways have come under threat from the largest human population on the archipelago, and meets a man on a mission to protect this iconic creature. Finally, Liz dives into the deep blue waters to witness the birth of a brand new island. Coming full circle, Liz and the team are able to reflect on the importance of their missions which will help to protect the Galapagos and its extraordinary wildlife in the future. In an ever-changing world, what we learn now from these incredible living natural wonders and what we can pass on to future generations has never been more important.