The world’s largest religious monument. 12th century.
Co-ordinates for world map: 13.412500, 103.866700
It’s a starred landmark and shows up on the map if you filter to show landmarks. When I was there last night, there were a bunch of other players flying around it too.
Real shame that none of the rest of the ancient city of Angkor or dozens of other temples and buildings on that site are rendered.