Secrets of the first people to make this unforgiving landscape home : The towering Himalayas were among the last places on Earth humans settled. We know this because humans need a special genetic adaptation to survive there and live permanently at the roof of the world. Scaling sheer cliff sides, a team of climbers and scientists hunts for clues to when the early people came to settle the forbidding landscape, where they came from, and how they adapted to survive the high altitude. Scattered across the dramatic cliff faces of the Mustang region of Nepal, thousands of cliff-top caves, which no modern humans have entered, could hold tombs embedded deep within the mountains. An expert team set out to find the ancient tombs. They discover caves filled with human bones and artefacts that date from 2,800 BC to 650 AD, including gold masks and Chinese silk. Who were these ancient mountain people and where did they come from?