Backing onto the Roman Forum, this 6th-century basilica incorporates parts of the Foro di Vespasiano and Tempio di Romolo , visible at the end of the nave. The real reason to visit, though, is to admire the church's vibrant 6th-century apse mosaics, depicting Peter and Paul presenting saints Cosma, Damiano, Theodorus and Pope Felix IV to Christ.
Also worth a look is the 18th-century Neapolitan presepio (nativity scene) in a room off the 17th-century cloister.
