Siem Reap and its gajillion of ruins:
Angkor Wat (the Hindu temple so famous they put it on the flag!) both at sunrise and in the heat of the afternoon.
Angkor Thom, the capital city of the Khmer Empire, and its Buddhist Bayon Temple
Banteay Srei, a pink gem of a palace at half-scale
Ta Prohm, the “Tomb Raider” temple, left in gorgeous ruins
and a whole bunch of lesser buildings that are collectively so gorgeous I had goosebumps. Sweaty, sticky goosebumps (because, hot and humid)