Temples in Cambodia
There's more to Cambodia than the temples around Siem Reap, but it'd be silly to act like they're not the main focal point.
The structures at Angkor Wat and Angkor Thom have been there since the 11th century, part of a city that was easily the largest in the world for hundreds of years. It's amazing to think about all the events that have taken place there and the people that have passed through.
Bayon, Baphuon, Phimeanakas.. they're all stunning. As are the trees at Ta Prohm, and the red sandstone at Banteay Srei. The 3 day temple pass ticket clearly isn't enough to take it all in, but it'll do for the first visit.
Take a look at all collections.