Wildest: India

Covering 200,000km sq, India’s Thar desert is one of the harshest places on Earth. Desiccating winds and near-permanent drought have earned this unforgiving land another name: the region of death. Temperatures soar to 50C and less than 5cm of rain falls each year.

The Ganges is the longest river in India. It flows from the glaciers of the world's highest mountains, the Himalayas, to the largest bay in the world, the Bay of Bengal. It’s a lifeline to wild animals, from India’s one-horned rhinoceros and the river dolphin to families of smooth-coated otters.

The Himalayas run across 2,500km of north India. Outside Asia, no peaks reach above 7km, but along the Himalayan range, over 100 mountains exceed this height. It is the tallest mountain range on the planet, by a long way.

Stretching for a thousand miles along India’s west coast, the Western Ghats is a spine of mountains that lay claim to being one of the most bio-diverse places in the world. On the eastern side of the mountains, in their rain shadow, tigers and wild dogs compete for prey in the dry forests.

North-east India is an anthropological paradise; there is no other place on Earth with so many different ethnic groups. The forest slopes are filled with mysterious tribes whose lives are dictated by the ebb and flow of the rain and the seasonal fruits of the forest.