San Nicola in Carcere
San Nicola in Carcere is located close to Teatro di Marcello in Rome.
The first church on the site was probably built in the 6th century, and a 10th‐century inscription may be seen on a fluted column next to the entrance, but the first definite dedication is from a plaque on the church dating to 1128.
Columns of the Temple of Speranza in the wall of the Church.
It was constructed in and from the ruins of the Forum Holitorium and its temples, along with a jail (carcer) which a tradition (supported by Pliny's history of Rome) states was sited in the temples' ruins. However, the in Carcere (in jail) part of the name of the church was only changed to "in Carcere Tulliano" in the 14th century, owing to an erroneous identification. The prison was really that of Byzantine times (LPD i.515, n13; ii.295, n12).
Spolia from all these ancient remains is still apparent in the church's construction, most particularly three columns from the Temple of Juno Sospita which are incorporated into both the 10th century and 1599 north facades of the church.
The dedication to St Nicholas was made by the Greek population in the area. In the 11th century, it was known as the church of Petrus Leonis, referring to the converted Jewish family who rebuilt the nearby Theatre of Marcellus as a fortress.
The church was rebuilt in 1599, with a new facade by Giacomo della Porta (though the medieval campanile — originally a fortified tower, then adapted to a bell tower after being abandoned — was not altered). Stairs under the altar lead to the crypt and to the base of the former Roman temples.
San Nicola in Carcere, Via del Teatro di Marcello, 46, 00186 Rome, Italy, Google Maps