Angkor Wat is the largest religious monument ever built and the centerpiece of an archaeological complex that once supported over a million people — the biggest city on earth in its time. The temple itself, with its five lotus-bud towers and nearly two hundred meter moat, is only the beginning. The wider Angkor area covers some four hundred square kilometers of temples, reservoirs, and ruins stretching through the Cambodian forest north of Siem Reap.
The scale of engineering here is staggering. Two hand-dug reservoirs — the Eastern Baray (7 km by 1.8 km) and the Western Baray (8 km by 2.3 km) — fed the rice agriculture that sustained the Khmer Empire. French explorers rediscovered the "lost city" in the late nineteenth century, though locals had never really forgotten it.
The three temples that draw the most visitors are Angkor Wat itself, Angkor Thom with its face-towers at the Bayon, and Ta Prohm, the jungle temple left largely as the explorers found it. Plan to visit more than once — the light changes everything, and there is far too much to absorb in a single day.