Angkor Wat is the capital of a Khmer kingdom located in Cambodia that lasted from the ninth to the 15th centuries, and at its height dominated a wide band of Southeast Asia, from Myanmar (Burma) to the west to Vietnam in the east. As many as 750,000 people lived in Greater Angkor, an area of almost 400 square miles, making it the most extensive urban complex of the preindustrial world.
Although economic and religious turmoil may have hastened Angkor's downfall, when continual maintenance of its intricate system to store water and control its flow began to falter, Angkor's power began to subside. By the 16th century power shifted from Angkor toward Phnom Penh after a period of erratic monsoons.