Breaking from the Shaiva tradition of previous kings, Angkor Wat was instead dedicated to Vishnu. As the best-preserved temple at the site, it is the only one to have remained a significant religious center since its foundation. The temple is at the top of the high classical style of Khmer architecture, which received major influence from Kalinga architecture. It has become a symbol of Cambodia, appearing on its national flag, and it is the country's prime attraction for visitors.
Angkor Wat (meaning “City Temple”) is the most magnificent and largest of all Angkor temples. The structure occupies and enormous site of nearly 200 hectares (494 acres). A huge rectangular reservoir surrounds the temple which rises up through a series of three rectangular terraces to the central shrine and tower at a height of 213 meters (669 feet). This structure reflects the traditional Khmer idea of the temple mountain, in which the temple represents Mount Meru, the home of the gods in Hinduism.
Angkor Wat is beautiful in both sunrise and sunset time. If you can, go all the way to the top for the best views. Also try to get lost in one of the side alleys for unique scenes.
It is much better if there is a professional guide accompany you and show you the meaning of the special sculpture as well as the position to take the best photos.
You should try the Balloon Ride over Angkor Wat (watch the sunset and overview of Angkor Wat).