narthex (närˈthĕks) [key], entrance feature peculiar to early Christian and Byzantine churches, although also found in some Romanesque churches, especially in France and Italy. Usually extending across the entire west front of the building, it was a vestibule for the penitents and catechumens who were not admitted to the church proper. The narthex was either enclosed within the building (often separated from the nave by a mere screen of columns) or consisted of an exterior colonnaded or arcaded portico. In the latter case it was sometimes merely a continuation of the atrium, as in a number of Italian basilical churches, including the original basilica (4th cent.) of St. Peter's Church, Rome. The inner narthex was particularly characteristic of the monastic churches, where admission was restricted. In churches having both types of narthex, as in Hagia Sophia, Constantinople (originally a Christian church), the outer one is termed exonarthex. With the growth of unrestricted entry into the churches, the narthex served no further ritual purpose after the 13th cent. The deeply recessed portals of Gothic cathedrals are derivatives of the narthex.