Angkor Wat is the centerpiece of the Angkor Archaeological Park. It was built as a Hindu temple in the 12th century during the reign of Suryavarman II. It's the most popular place to view the sun as it rises above the temple complex. At sunrise, most tour groups go inside the walls as many individual travelers (with their tour guides) stay outside the moat. Since Angkor Wat is west-facing, I love to visit this temple in the late afternoon when the setting sun brings out the earthen colors of the walls and buildings.
If you're interested in visiting Angkor Wat, take a look at our post about planning a trip to this amazing 12th century temple complex. If you'd like to see a photo tour of another ancient temple at Angkor, read our post about the stone faces of Bayon.