Despite dating from the 8th century, this glorious basilica was almost entirely rebuilt at the end of the 16th century. Its huge, gold-stuccoed interior features paintings by Massimo Stanzione and Paolo de Matteis and a striking geometric floor by Nicola Tammaro. Top billing, however, goes to the sumptuous sacristy, lavished with luminous frescoes by baroque-meister Francesco Solimena.
Built in 1603, the double staircase adorning the basilica's main facade is the work of Francesco Grimaldi. Much older are the two columns flanking the entrance, taken from the Roman temple to Castor and Pollux that stood on the site.