Founded around 640 AD by the hermit monk Rabban Hormizd, this cliffside sanctuary is carved into the mountain rock above Alqosh. Between the late 15th and 18th centuries, it served as the official seat for patriarchs of the Church of the East, and in 1553, abbot Yohannan Sulaqa entered union with Rome, marking the creation of the Chaldean Catholic Church. Today, visitors can see historic patriarchal tombs and rock-cut hermit cells. For more: Christian Heritage in Northern Iraq: A Guide to Alqosh, Mar Mattai, and the Nineveh Plains