Formerly one of the largest monasteries in Mongolia, Ongi monastery was founded in 1660 and consisted of two temple complexes on the North and South banks of the Ong river. The older southern complex consisted of various administrative buildings as well as 11 temples. The northern complex built in the 18th century, consisted of 17 temples-among them one of the largest temples in all Mongolia. The Ongi monastery grounds also 4 Buddhist universities and could accommodate over one thousand monks at a time. During the 1930’s communism spread throughout Mongolia. As part of their ideological campaign and rise to power, communists arrested most monks around Mongolia. In 1939 Ongi monastery was completely destroyed over 200 monks were killed and many surviving monks were imprisoned pr forced to join the communist controlled army.
Other monks were escaped certain death by becoming farmers and common workers. The water from the river was re-routed to support local mine, which were run by the Communist government. When the river dried out, Local communities were forced to leave surrounding areas of monastery. With the departure of both monks and locals, ongi monastery seemed destined to disappear. However, democratization of Mongolia in 1990, three monks returned to Ongi monastery whre they had begun their Buddhist education as young children some 60 years prior. These monks started laying new foundation upon the old ruins, with a vision to restore Ongi monastery and revitalize Buddhiam in Mongolia. Around the Ongi monastery there are some tourist camps.