"Traversing some of the highest terrains in the world, the Qinghai-Tibet Railway, in service since July 2006, makes the 4,064-kilometer trip from Beijing to Lhasa in 48 hours. It climbs to an ear-popping altitude of 5,072 meters above sea level passing through several tunnels that had to be carved out of frozen soil. It carries a wide range of passengers from businessmen seeking opportunities in Lhasa to pilgrims to the Potala Palace. They travel together along the "rooftop of the world." High Clouds Railway to Tibet showcases the magical allure of this breathtaking railway, including the latest technology used to overcome the harsh conditions like the icy ground and thin air."