The myth of Shangri-la originates in Tibetan Buddhist beliefs in beyul, or hidden lands, sacred sanctuaries that reveal themselves to devout pilgrims and in times of crisis. The more remote and inaccessible the beyul, the vaster its reputed qualities. Ancient Tibetan prophecies declare that the greatest of all hidden lands lies at the heart of the forbidding Tsangpo Gorge, deep in the Himalayas and veiled by a colossal waterfall. Nineteenth-century accounts of this fabled waterfall inspired a series of ill-fated European expeditions that ended prematurely in 1925 when the...