 Owing to the barrel ceiling within the nave, the church facades are reinforced with lateral exterior buttresses (some staggered examples are not original to the main building and may have been added in the 17th–18th century).These large buttresses support the lateral facades and are interspersed by cornices.The south facade has a single portico with semi-circular archway, comparable to the principal facade but in a smaller scale (but with four columns on capitals and with bird and flower motifs).