Nagarjuna Sagar Dam is one of the largest dams built in Asia, located between the cities of Guntur and Hyderabad. It is located in Nalgonda district, Andhra Pradesh (India). It is built on the Krishna River between Guntur and Nalgonda districts. It is one of the earliest hydro-electric projects of India. Nagarjunasagar dam, which was completed in 1966, is 124 metres high and 1 km long, and has 26 crest gates. Located at a distance of 150 km from Hyderabad, Nagarjunasagar is an important irrigation dam on river Krishna. This is the tallest and biggest masonry dam in the world. It creates the third largest man-made lake in the world. Apart from this, remains of the Buddhist civilization dating back to the 3rd century A.D, are seen on an island called Nagarjunakonda located in the midst of the reservoir. These relics of Buddhist civlization found during excavations unveiled a great Mahachaitya, the most sacred of the stupas. An inscription in Brahmi characters states that the sacred relics of Lord Buddha lie within the Mahachaitya. Now it has become one of the major tourism destination, and weekend destination for Hyderabadis.