In 1586, Erdenezuu, the oldest surviving buddhist monastery in Mongolia was built on the ruins of the 13th century capital. The Avtai Sain Khan, ruler of the Khalkh Mongols and grandfather of Zanabazar, the first Jebtsundamba Khutuktu, ordered construction of the Erdenezuu Monastery in 1585 after his meeting with the III Dalai Lama and the declaration of Tibetan Buddhism as the state religion of Mongolia. Erdenezuu Monastery is part of the Orkhon Valley Cultural Landscape World Heritage Site. In the early 20th century Erdenezuu was walled monastery with 108 stupas (108 being a sacred number in Buddhism), about 60 temples, and housed up to 1500 monks. Tourists can visit the "Karakorum" and "Erdenezuu" Museums, where about 7,900 exhibits are preserved in "Erdenezuu" Museum and in the other museum are stored precious heritages of Stone Age, Bronze Age, as well as exhibits displaying eras of early States, Great Mongol Empire and Mongolia's ancient capital city of Karakorum.