Planet Earth

There would be no life on land without fresh water. But it's the sun that really defines the habits of plants and animals. See how factors like these have worked together to shape the planet's natural history.

Travel to some of the world's mightiest mountain ranges. Start at one of the lowest places on Earth and end at the summit of Mount Everest, uncovering some of the planet's most secretive animals along the way.

Follow the long and winding descent of rivers, from mountaintops to ocean. See how freshwater sources from around the world control the distribution of all terrestrial life.

Explore one of the only habitats not driven by sunlight. Go deep inside the world's largest natural caves, caverns, and tunnels to uncover the secret worlds that live inside.

Get a closer look at the earth's deserts, which make up a staggering 30 percent of its surface and are home to some of the most interesting mammals on the planet. Travel from Mongolia to Chile to find out how these rare creatures survive.

Trace the footsteps of the great polar explorers into the most remote wildernesses on the planet. With the help of Royal Navy helicopters, journey to the polar extremes of our planet, which undergo extreme seasonal transformations.