In 1860 the French naturalist Henri Mouhot came upon an enchanting temple buried in the jungle of western Cambodia. It thrust spires of finely carved sandstone into the sky, and its open galleries held an artistic treasure: more than a mile of delicate bas-relief stone panels. "It is grander than anything left us by Greece and Rome," wrote Mouhot in his diary.
The temple, called Angkor Wat, was the work of the ancient Khmer kings of Angkor, whose empire stretched from what is now southern Vietnam to Burma. Today a first-time visitor may feel like a modern Indiana Jones who spies...