The Basilica di San Nicola in Carcere is a church in Rome with an interesting history. It was built on top of three ancient temples, and pieces of these temples were incorporated into the facade of the current church. There are columns and other sections from the Temple of Spes dating back to 250 B.C., a temple that honored Juno from the 2nd century B.C. and rebuilt in 90 B.C., and the Temple of Janus, the god of gates and beginnings, dating to 17 A.D. Unlike most churches in Rome that took columns from other ruins around the city and moved them, the columns in this church still stand in their original location.
Since the ground level was much lower 2,000 years ago, some of the ruins of these temples are now underground. Visitors can take a tour beneath the church to see these ruins, which are older than many other ruins in the city. These ruins are Republican era, making them roughly 500 years older than the imperial era ruins in other parts of Rome.