The Angkor Archeological Park contains a complex of temples begun in the early 1100's under the reign of King Suryavarman II. These people had migrated from southern India, and it was originally built as a Hindu temple. After the king's death in 1150, work appeared to stop. Then in 1177, approximately 25 years later, Angkor was sacked by the Chams. Under Cham rule, the temple was gradually turned into a Buddhist temple.
Angkor Wat is the primary temple in the complex. The scale of this temple is massive – the outer walls walls are over 2 miles around, and the enormous moat is over 600' across! The aerial photos below give a good sense of the layout and hopefully the scale.
Sunrise and sunset are great times to visit the temple, and these people are waiting to watch the sun rise.