The Umayyad Mosque, also known as the Great Mosque of Damascus (Arabic: جامع بني أمية الكبير‎, Romanization: Ğāmi' Banī 'Umayya al-Kabīr), located in the old city of Damascus, is one of the largest and oldest mosques in the world. It is considered by some Muslims to be the fourth-holiest place in Islam.After the Arab conquest of Damascus in 634, the mosque was built on the site of a Christian basilica dedicated to John the Baptist (Yahya), honored as a prophet by Christians and Muslims alike.