It is located in Saihan-Ovoo Soum of Dundgovi province. One of the biggest monasteries in Mongolia, Ongi, was founded in 1660 and consisted of two temple complexes on the North and South banks of the river Ongi. At its heyday, Ongi monastery consisted of over 30 temples, 4 big Buddhism universities and over 1000 monks at a time. During 1930s, communism spread throughout Mongolia. Both complexes of Ongi Monastery were completely destroyed in 1939 during anti-religious purges, over 200 monks were killed, and many surviving monks were imprisoned or forced to conscript into the Communist controlled army. Other monks escaped becoming farmers and common workers. In 1990, after the democratization in Mongolia, some monks returned to the monastery and began their Buddhist education as young children some 60 year prior. At present, one temple has been fully rebuilt, small museums and ruins of the temples.