One of the most popular temples in the Angkor Wat Complex is Ta Prohm. The location of Lara Croft: Tomb Raider (2006) starring Angelina Jolie, this temple is a frequent stop on tours of Angkor Wat, especially with American tourists. Even if you haven't seen the movie, I recommend visiting this temple on your trip to Siem Reap, Cambodia.
I think Ta Prohm was my favorite of our trip. It has unfortunately suffered a lack of maintenance, and nature is retaking the land. The way the trees have grown is amazing to see. These trees are the result of bird poop landing on top of the temple, presumably in small amounts of soil or, more likely, moss built up on the stone. You can see the roots of the trees come down any way possible to make it to more stable ground.
The trees at Ta Prohm temple are called silk-cotton trees, and they are fast-growing, light, and actually hollow. This is how they manage to sit atop the temple without causing more damage than they otherwise would. The result is something that looks impossible and exotic and very photogenic. If you go to Ta Prohm, make sure to take some vertical panoramic photos so you can get the whole tree in the shot!
It wasn't just the trees that I enjoyed, though. The stones were colorfully filled with moss and red that had been painted on centuries prior. There was also a window totally overtaken by a beehive, which was something I'd never seen before. There was also this small structure that resonated low frequencies really well. Because of this, locals leave money in it.
Angkor Wat felt like walking through an archaeological site, but Ta Prohm felt like discovering ruins in the jungle. It is clear why it was chosen for a movie called "Tomb Raider," and I really enjoyed exploring it.