Holy Apostles Church The Holy Apostles Church, also known as the Cathedral of Kars, is a 10th century structure located in the heart of Kars. Throughout its history, it has served as an Armenian Apostolic church, a Russian Orthodox cathedral, and a Turkish mosque. In 1993, the church was converted into a mosque and given the name Kümbet Mosque. Today, it is part of a larger Muslim complex that includes the Evliya Mosque, one of the largest mosques in Kars. The church features a central plan with a domed tetraconch and is modeled after the seventh-century Church of Saint John in Mastara. The main entrance is located on the western side, while two additional entry points can be found on the south and north sides. Externally, four dihedral angles protrude from each of the four cardinal directions and lead into an octagonal extension, which features seven additional bays before forming a curved dome in the front or back. The naves terminate at opposite ends and are clearly visible externally, where right angles overlap three meters past into external walls that mirror them inside. The four articulated corners are made up of cylindrical squinches centered over a square.