The Sanahin Monastery was founded in the 10th century during the reign of King Abbas Bagratuni. The complex includes the Surb Astvatsatsin Church (951), the Amenaprkich Church (957–966), the Surb Grigor Chapel (1061), a scriptorium (1063), an academy, a narthex (1181), a bell tower (13th century), and the family tomb of the Zakharyan princes. The monastery is built of grey basalt, the facades of the buildings are smooth and monolithic, and the interiors are decorated with carvings and bas-reliefs. Burials of nobles took place in the narthexes and galleries. The monastery had a higher school, vardapetaran, where philosophy, rhetoric, and mathematics were taught. In the 11th–13th centuries, Sanahin was a major center of education, theology, and manuscript copying. Large-scale restoration work was carried out in 1652. In 1996, the monastery was included in the UNESCO World Heritage List. Near the monastery there is a single-span arched bridge across the Debed River, built in 1192. Numerous khachkars have been preserved on the territory of the complex, including the tombstone of Archbishop Grigor Tuteord (1181–1184).