Siem Reap monuments

Angkor Thom

Angkor Thom is one of the capital cities of the ancient Khmer empire. It's a sprawling complex, with many interesting monuments within like the Bayon temple, Victory square, Baphuon and terrace of the Lepper King. The site is amazingly preserved, and you're allowed access to most of the monuments. Lots of scrambling up and down stairs and exploring long corridors makes for a fun afternoon. The place is so big you hardly feel the tourist crowd.

Angkor Wat

How can you go to Siem Reap without visiting the granddaddy of all monuments, Angkor Wat. It's a temple complex from the 12th century which has gone through a few religion changes. Each time that happens, the statues gets replaced/defaced, which is why most of the Buddha statues are headless/armless. Nevertheless, it's an amazing sight to behold. The long corridors that go around the complex have bas reliefs that go on and on.. don't forget to check out the Churning of the Sea of Milk, which is on the Eastern end of the galleries. The inner complex is not nearly as fun to explore as the Bayon, mainly because access to the upper levels and middle towers are closed off to visitors.

Ta Phrom

One of the 'jungle temples' in the region, it has been left almost in the same state that it was found in. The jungle is seemingly eating up the temple, and the temple is bravely holding it back. It's a fascinating place to explore, and yes, they did film Tomb Raider here.

Phnom Bakheng

It's a hindu temple on top of a mountain. The walk up might be tiring for some, and then there's a climb up really steep stairs, but the view from the top is worth it. You'll get a great view of the expanse of rice paddy fields below. If you bring a very good zoom lens, you could even take pictures of Angkor Wat from there. The temple itself isn't much more than a room on the top

Beware the throngs of tourists rushing up the mountain just before sunset (and probably sunrise). If you are going to join them, bring a torch because there are absolutely no lights along the path.

Banteay Srei

Banteay Srei is a remarkably preserved temple from the 10th century. It's built from red sandstone, and has amazingly intricate carvings. The temple complex itself is small compared to the later Angkor monuments, but you'll spend so much time gawking at the carvings that you'll forget how small it is. The inner sanctuary can only be seen from the perimeter, but the rest of the temple is open for exploration. Definitely worth making a stop here if you're in the area.