Drought Led to Demise of Ancient City of Angkor

...The great city of Angkor in Cambodia, first established in the ninth century, was the capital of the Khmer Empire, the major player in Southeast Asia for nearly five centuries. It stretched over more than 385 square miles (1,000 square kilometers), making it the most extensive urban complex of the preindustrial world. In comparison, Philadelphia covers 135 square miles (350 sq. km), while Phoenix sprawls across more than 500 square miles (1,300 sq. km), not including the huge suburbs....