The Nagarjuna Sagar project is built on the Krishna River, near the Peddavoora Mandal in Nalgonda District.
 This is an irrigation dam and it is the largest masonry dams in the world. Because the dam is so big, it also creates the third largest man-made lake in the world. There is an island on the manmade lake, which is called Nargarjunakonda.

The remains of a Buddhist civilization are situated on this island, dating back to the 3rd century AD. The remains of the Mahachaitya are also found here. The Mahachaitya is the most sacred of the stupas.

Excavations in this area have also revealed the remains of a university, vihara and monasteries. The university was under Acharya Nagarjuna, who was a Buddhist saint and scholar. The Buddhist University was found, during the excavations made during the construction of the dam.