IntroductionAngkor (ăngˈkôr) [key], site of several capitals of the Khmer Empire, north of Tônlé Sap, NW Cambodia, for about five and a half centuries (9th to 15th), the heart of the empire. Extending over an area of 120 sq mi (323 sq km), the ruins contain some of the most imposing monuments in the world, including about a thousand temples, mainly Hindu and some Buddhist; the ancient city, however, had an extent perhaps nearly 10 times that size (according to satellite photographs published in 2007), and was home to perhaps 750,000 people. The earliest temples were constructed of brick, the later of stone, and many are covered with elaborate sculptures. The Angkor site also contains palaces and other buildings associated with the Khmer state. The first capital of the empire was founded by Yasovarman I (r. 889–900) and was centered around the pyramidal temple of Phnom Bak Kheng.