It is the only church to have kept the altar facing East. Originally dedicated to the Madonna of Loreto, as evidenced by the fresco by Vima (depicting the homonymous Madonna with St. John the Baptist and the Archangel Gabriel), it changed patron after 1644, when Pietro Novelli painted the fresco of St. Antonio , now preserved in the church of S. Giorgio. The church has an imperfect Greek cross. The side walls are decorated with two mosaics by Dixit Domino depicting St. Catherine and St. Anthony the Great.