Beneath the 5th-century Basilica of SS. Giovanni e Paolo lies a fascinating archaeological site: A complex of Roman houses of different periods—a wealthy family’s townhouse from the 2nd century A.D. and a 3rd-century-A.D. apartment building for artisans. According to tradition, the latter was the home of two Roman officers, John and Paul (not the Apostles), who were beheaded during the reign of Julian the Apostate (361–63) for refusing to serve in a military campaign. They were later made saints, and their bones were said to have been buried here. The two-story construction also contains a small museum with finds from the site and fragmentary 12th-century frescoes.