Just like Ta Prohm, the Preah Khan temple was built by/for Jayavarman VII in the 12th century. This temple is mostly flat in design and much unrestored, so there are trees and other vegetation growing through and around the actual temple. Just magic to walk around here and wonder how life actually was here some 1000 years earlier.
Ta Prohm, outside of Angkor in Siem Reap province, Cambodia, is one of the most amazing temples to visit, period. The temple, built from the 12th-13th century, in Bayon style, is kept almost untouched from restoration (even though restorations were ongoing in July 2012). It was founded by Khmer King Jayavarman VII as a buddist monastery and university.