While Tibetan Buddhism is squeezed inside of China's borders, there is a place where it still survives intact: Upper Mustang - a once forbidden kingdom high in the Nepalese Himalayas.
Steve Chao travels there to document the fight to preserve an ancient culture, as China expands its influence into Nepal, and the modern world slowly creeps in.
There is a reason for China's concern. In the 1960s, shortly after the Dalai Lama fled Tibet for India, a Tibetan resistance movement was formed in a place called Mustang.
Mustang, or Lo, as locals call it, is an ancient Tibetan kingdom that is now part of Nepal. Hidden in the Himalayas, the world's highest mountain range, it is protected by its remoteness, and the fact the only way in and out for centuries was on horseback.