Jetawanaramaya Stupa, one of the largest structures of the ancient world

Schoolchildren walking around the Jetavanaramaya Stupa, one of the largest structures of the ancient world, in Anuradhapura. Some 93 million bricks were used to build the Jetavanaramaya, a stupa built under the King Mahasen who ruled the country from 277 to 304 AD, and was the tallest stupa in the world at the time of its construction (Alex OGLE / AFP)