Covering 200,000 square kilometers, India’s Thar Desert is one of the harshest places on the planet. Baking heat, desiccating winds and near permanent drought has earned this unforgiving land another name – “the region of death.”

Temperatures often soar to over 50 degrees C and less than 5cm of rain falls each year. Despite the lack of food and water, the Thar is a hotspot for nature and home to some of the toughest and rarest creatures on earth – including man.

Humans have flourished here since the Stone Age, forging incredible alliances with the region’s animals in order to survive.

As we explore India’s great desert we unveil its hidden secrets, and ultimately shed light as to how the Thar has become the most crowded desert in the world.

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 rare one-horned rhinoceros and the elusive river dolphin, to families of smooth-coated otters that dart through the water hunting fish in a pack and the bizarre long-nosed gharial that is found nowhere else in the world. Eight percent of the world’s population live in the Ganges river basin and depend on the river for their livelihoods. But to Hindus the Ganges is far more than a river; she is a goddess. Millions of pilgrims come to the Ganges to wash in her holy waters every year, and for many the Ganges is the final resting place for their earthy bodies. At Varanasi, the holy city at the heart of the Ganges, over two hundred cremations are carried out on the riverbanks every day, their ashes scattered in the Ganges. Human pollution threatens to overwhelm the river, but somehow wild animals survive. Hindus believe that Ganges water has the power to purify, and it seems there is some scientific evidence to support this conviction: microscopic organisms actually eat bacteria that could cause disease, and uniquely high level levels of oxygen break down organic waste faster than any in other river. This self-cleaning property of Ganges water helps support some of the last remaining true wilderness in the world – the Sundarbans swamp. Here, India’s largest population of wild tigers have never learned to fear man, making them very dangerous neighbours.

The Himalayas run west to east across Northern India forming an arc 2,500km long. Outside Asia, no peak reaches above 7000 metres, but along the Himalayan range, over 100 mountains exceed this height by at least 200 metres, making it the tallest mountain range on the planet. As Earth meets the sky along this hostile terrain, powerful winds, sub-zero temperatures, and a lack of oxygen oppose virtually all forms of life, but remarkably, this immense geological feature somehow supports one of the largest and most diverse collections of creatures on the planet – including man. Nomadic Pashmina goat herders are continually forced to alter the altitude they live at. At 5000 meters above sea level, winter temperatures can plummet to minus 50 degrees Celsius, so the Changa tribe head to slightly lower plains where mercury levels drop to a more manageable minus 30. But freezing temperatures aren’t the only challenge facing this small community of farmers. Snow leopards looking for easy meals encircle the nomads’ makeshift camps – protecting their goats and livelihood is a continuous battle. While the Himalayas rugged highlands offer little direct refuge to humans, in the shadow below, over a billion people in India rely on the mountains for survival. As the seasons come and go, it soon becomes clear how these mountains fuel such a vast array of life.

Stretching for a thousand miles along India’s west coast, the Western Ghats are a spine of mountains that lay claim to being one of the most bio-diverse places in the world. Mountains rear their heads into the path of monsoon clouds, intercepting rains and making the western slopes some of the wettest places in India. Tropical rainforests thrives, and explode with life. Endangered lion-tailed macaques share the fruits of the jungle canopy with giant squirrels; among the leafy the branches, an emerald-green vine snake stalks a flying lizard; and on the forest floor below the largest venomous snake on the planet rules supreme – the mighty king cobra. On the eastern side of the mountains, in their rain shadow, tigers and wild dogs compete for prey in the dry forests. The Western Ghats hold the key to life across southern India. Rainwater harvested by the mountains washes down to the coast, feeding Kerala’s backwaters; huge rivers flow east across India’s dry interior, a lifeline to animals and people. Exploited by man in the last century for the cultivation of tea and spices, the Western Ghats have been home to people for thousands of years. An innate respect for the natural world still runs deep in local cultures: many would rather abandon their homes than harm the king cobra sleeping inside, and there are few spectacles in India as wild as the Huli Vesha tiger dance.

Imagine a lost world…head hunting tribes, tiger-infested forests, unclimbed mountains, pristine rivers. Known as the Seven Sisters of India, there are seven relatively unexplored and isolated Indian states. What mysteries lie within this secretive land and why have they remained untouched for so long? Hundreds of years of conflict combined with geographical isolation have meant that India’s north-east territories have been closed to foreigners for many years. They are bordered by the Himalayas to the North and the Indian Ocean to the south. In this lost world, the jungle clad mountains create their own weather systems where condensed moisture falls as almost continuous rain. Everywhere here water drips, flows, trickles or pours. Plants grow at an astonishing rate, providing homes to larges numbers of insects, birds and animals. Nestling in the foothills of the Himalayas is a wet, green, dense world of mountainous jungle, harbouring all kinds of life from bears and jackals to pythons, rare monkeys and elephants. 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. In these largely unexplored and isolated areas people scarcely known to the Western world continue a way of life steeped in ancient rituals.