Santi Cosma e Damiano

Built into the original 4th-century Templum Pacis (Forum of Vespasian) in 527 AD by Pope Felix IV — making it one of the oldest churches in the Forum complex. The 6th-century apse mosaic is an extraordinary Byzantine-style work showing Christ in glory between Saints Cosmas and Damian (the patron saints of doctors and pharmacists, who were twin brothers). The 18th-century Neapolitan-style nativity scene displayed permanently in a side room is one of the largest in Italy.