Coptic Cairo is a part of Old Cairo which encompasses the Babylon Fortress, the Coptic Museum, the Hanging Church, the Greek Church of St. George and many other Coptic churches and historical sites. It is believed in Christian tradition that the Holy Family visited this area and stayed at the site of Saints Sergius and Bacchus Church (Abu Serga). Coptic Cairo was a stronghold for Christianity in Egypt both before and during the Islamic era, as most of its churches were built after the Muslim conquest of Egypt in the 7th century.