Probably once covered by a dome, the basilica’s central octagon is distinguished by eight basalt Corinthian columns, contrasting with the atrium’s milky-white column shafts. This layout pins down construction to the 5C-6C. On a hillside site, its altar was separated from the nave by a chancel. Opposite, a narthex preceded the basilica. Symbolising the passage from the terrestrial to the celestial realms, the ambulatory is attractively paved in polychrome geometric tiles.