Once we left Çoruh Valley, we made a short detour to visit the majestic ruins of the tenth-century Georgian monastery of Oshki. It is considered one of the four Great Cathedrals of the Georgian Orthodox world. It was built during the reign of David III Kuropalates, the ruler of Tao-Klarjeti and an ally of the Byzantine Emperor. The church follows a Latin cross plan, with triconch ends on three arms, and is crowned by a high conical dome. In the sixteenth century, this region was absorbed by the Ottoman Empire, and its many monasteries were forsaken. For a time, Oshki was used as a mosque after the conversion of the local population to Islam but was eventually abandoned. As a result, this 1,000-year-old church has suffered heavily from prolonged neglect. Over time, large areas of the vaults have collapsed, and today many parts of the church are in terrible condition.