Tiger’s Nest Monastery, perched precariously on the edge of a 3,000-feet-high cliff in Paro Valley, is one of the holiest places in Bhutan. Legend has it that Guru Rinpoche [wiki], the second Buddha, flew onto the cliff on the back of a tigress, and then meditated in a cave which now exists within the monastery walls.
The monastery, formally called Taktshang Goemba, was built in 1692 and reconstructed in 1998 after a fire. Now, the monastery is restricted to practicing Buddhists on religious retreats and is off-limits to ordinary tourists