The Red Sea is one of the youngest oceans in the world and one of the warmest. The northern region, with its diverse array of marine life, is one of the most visited dive locations on earth while the southern end remains virtually unexplored. It's a global hotspot for marine biology and an important trade route throughout human history, linking the trade goods of India and the Far East with the markets of Egypt and Europe.

The Indian Ocean is the third largest body of water on Earth at more than 6,000 miles wide and covering 13% of the world's surface. It is home to 5,000 species of fish, many of which only exist in the Indian Ocean. But it is also an ocean under threat from global issues such as over-fishing and climate change, which make this an ocean on the edge.

The tropical Indian Ocean is home to the Spice Islands. Characterised by beautiful sandy beaches, fringing coral reefs and coastal mangrove forests, this is a vibrant nursery area for marine life, such as whale sharks, crabs, seahorses and a great variety of fish. The coastal areas are where humans have the most direct impact on the ocean's resources.

With much of it covered in ice all year round and with no daylight from October to March, the Arctic Ocean is one of the world's most remarkable oceans. Its home to a multitude of unique life forms, all highly adapted to cope with the extreme and seasonal conditions. The impacts of climate change are more strongly felt here than anywhere else in the world.

Welcome to an extreme landscape of rock, ice and snow. We tour the mightiest mountain ranges, starting with the birth of a mountain at one of the lowest places on Earth and ending at the summit of Everest. Find out how some of the most secretive animals rise to the challenge of mountain life. Share one of Earth's rarest phenomena, a lava lake that has been erupting for over 100 years. The same forces built the Simian Mountains where we find troops of gelada baboons nearly a thousand strong. In the Rockies, grizzlies build winter dens inside avalanche-prone slopes and climb the peaks to devour abundant summer moths. In another world first, the programme brings us astounding images of a snow leopard hunting on the Pakistan peaks.

Fresh water is our most precious resource and it defines the distribution of life on land. Follow the descent of rivers from their mountain sources to the sea. Watch spectacular waterfalls, fly inside the Grand Canyon and explore the wildlife below the ice in the world's deepest lake. Witness unique and dramatic moments of animal behaviour: a showdown between smooth-coated otters and mugger crocodiles; deep-diving long tailed macaques; massive flocks of snow geese on the wing and a piranha frenzy in the perilous waters of the world's largest wetland.