The transept is oriented east to west and lit by two paired windows, each with a rose window above. Above the crossing of the transept is an octagonal tholobate supporting a dome of nine meters in diameter, composed of thirty-two ribs and crowned by a cross. Each outward face of the octagon contains a window flanked by two red granite columns and topped by a triangular pediment. The semicircular apse is adorned with five blind arches on the outside, each flanked by two red granite columns. The sacristy buildings that were added later hide part of the apse.