The location where this church rests has brought many questions to the minds of scholars. It is suspected that at one time, the location was a chapel as early as the seventh century, or a prison during the following century. It is believed that a church existed here in the ninth century, and it is known that since 1128, it has been a place of Christian worship. .
Today, the church of St. Nicola in Carcere can be found on a short street leading to the Tiber bank, just left of the Theatre of Marcellus. .
At one time, the whole area was controlled by the Forum Olitorium, or the vegetable and fruit market of ancient Rome. The market began as a simple place of commerce, but soon developed into a monumental center of temples and other public buildings. .
The Church is built on the site of three temples believed to have been dedicated to Janus, Juno Sospita and the Temple of Hope, all during the first Punic war (264-241 BC). The church is incorporated into the Temple of Juno Sospita, and is known for its use of Roman architectural palimpsest. .
Inside, the podium and some of the columns of the Temple of Hope can be seen on the right of the church, beside the campanile, which are all that remains of what was once a medieval tower. .
In 1599, Giacomo della Porta restored the church, adding the mannerist fa�ade. .
The name �in carcere� (in prison) caused confusion with the Mamertine prison, which was on the opposite side of Capitoline Hill. .