Following an epic spree of religious building whose scale and ambition rivals the pyramids of Egypt, Angkor is the scene of one of the greatest vanishing acts of all time. The Khmer kingdom lasted from the 9th to the 15th centuries and at its height dominated a large swathe of South-East Asia from Myanmar to the west to Vietnam in the East. As many as one million people lived in Angkor, the capital, which sprawled across an area the size of New York's five boroughs. By the late 16th Century, the once resplendent capital was being overrun by the surrounding jungles. 1300 carved inscriptions survive on temple doorjambs but the Khmer people of Angkor left not a single word explaining their kingdom's collapse.