Mamertine Prison

The Mamertine Prison, also known as the Tullianum, is an ancient subterranean detention complex near the Roman Forum in Rome. It is one of the earliest known prison sites in the city with retained Roman masonry.

Visitors encounter a compact underground cell with stone steps and masonry features, often presented alongside interpretive panels that explain its Roman use and later Christian traditions. The church of San Giuseppe dei Falegnami is built over the site and frames the entrance.

Used in Republican and Imperial Rome for the detention of high-profile prisoners, the site later became connected with Christian tradition that identifies it with the imprisonment of prominent early Christian figures. Over centuries the Tullianum was incorporated into later buildings, including the church above.

The prison complex lies at the foot of the Capitoline Hill, adjacent to the Roman Forum and close to the Tabularium and the Vittoriano monument in central Rome.

• Visiting conditions: Interior spaces are small, low and dimly lit; visitor access is usually brief and may be limited to small groups for preservation reasons.

What to See #

• Tullianum (subterranean cell): The subterranean chamber traditionally called the Tullianum is a low stone cell with an internal well or basin and Roman-period masonry, visible from controlled visitor walkways.
• San Giuseppe dei Falegnami (church): The small Renaissance-era church of San Giuseppe dei Falegnami stands above the prison and provides access and a visible marker for the site adjacent to the Roman Forum.