Treasure Seekers: Tibet's Hidden Kingdom.

In the 19th century, as it became aware of the colonial designs of European power on central Asia, Tibet expelled westerners and closed its frontiers. As its isolation deepened, so did Tibet's allure and mystique. But in the early 1900s, Francis Younghusband, a British colonialist, managed to penetrate the hidden city of Lhasa and bring to an end the country's years of isolation.