Beside the Roman Forum at the foot of Capitoline Hill, the Mamertine Prison is an underground archaeological site once used to hold Rome’s enemies. Its lower chamber, the Tullianum, is linked by Christian tradition to the imprisonment of Saints Peter and Paul before their executions; the evidence for Peter’s stay is not conclusive. Descend to see the confined cell and the opening in the floor. The visit is brief and solemn, with ancient stonework and early Christian history at its centre.
A Roman prison beneath the city
The Mamertine Prison, also called the Carcer Tullianum, stands beside the Roman Forum at the foot of Capitoline Hill. It was used as a state prison for Rome’s enemies, who could be held there before execution or public trial. The site’s history reaches back to at least the seventh century BC, and its use as a prison continued into the fourth century AD.
The structure has two levels. The upper chamber is known as the Carcer; below it is the Tullianum, the lower cell where prisoners were held. The compact underground spaces give the visit its particular character.
The tradition of Peter and Paul
Christian tradition holds that Saints Peter and Paul were imprisoned here before their executions. The association is especially significant to Christian pilgrims, but the evidence is not equally firm for both apostles: the case for Paul’s presence is stronger, while Peter’s imprisonment at this site is not proven.
The lower chamber is also associated with the story of Peter baptising his guards. An opening in the floor connects the upper and lower levels. The modern altar inside depicts Peter with keys and Paul with a sword, their traditional symbols.
Stonework and the lower chamber
The upper cell is built from large, squared stones fitted without mortar, a method known as opus quadratum. The lower Tullianum has an early barrel vault. These details offer a close look at Roman construction in a small space, alongside the site’s role as a prison.
The visit descends by stairs through the chambers. The lower cell is very confined, so an early arrival can leave more room for a quiet visit. Audio material is available through a guide or app, though the setup may take some attention.
Häufige Fragen
Where is the Mamertine Prison?
It is at Clivo Argentario 1, beside the Roman Forum at the foot of Capitoline Hill in Rome.
Were Saints Peter and Paul imprisoned here?
Christian tradition links both apostles to the prison. The evidence for Paul’s presence is stronger; Peter’s imprisonment here is not proven.
How long does a visit take?
The site is small, and a visit can be brief. Allow around 15 to 30 minutes to see the chambers.
Is it worth visiting before the Roman Forum?
The prison is beside the Forum and near the Septimius Severus Arch, so it can be combined with a Forum visit.
