Angkor Wat was really more of a fortress than it was a temple.
There is a massive moat that encircles the complex. I can only imagine how long it took peasants to dig a thousand years ago. I also wonder how they all drank fresh water back then. I know I couldn't go more than 10 minutes walking around the area without needing a drink. The massive heat, humidity, and standing water was a perfect recipe for cavalcade of bacteria to rise up and fight back. I don't suppose they all boiled their water. Maybe everyone was just more hardy back then... Luckily, when I was there, there were plenty of little children running around selling me bottled water. Which, upon further reflection, I probably should not have drank.
from the blog at www.stuckincustoms.com