The ancient Carcer Tullianum, also known as the Mamertine Prison, was a maximum security prison, which for many centuries housed the enemies of Rome, while awaiting their execution. According to tradition, the Apostles Peter and Paul were imprisoned here, shortly before they were to be martyred. Built around the 7th century BC on the slopes of the Capitoline Hill near the Roman Forum, the building consists of two superimposed floors. The deepest level is called the Tullianum, while the second, upper level is known as the Carcer. According to archaeologists, the latter dates back to the 6th century BC and has a large travertine façade, which is clearly visible from the city. Due to its strategic location at the foot of the Capitol and in front of the Forum, the prison served as a clear warning of Rome's justice to its enemies. Many historical figures were imprisoned there, such as Giugurta, King of Numidia in 104 BC, and Vercingetorige, King of the Gauls in 46 BC, who lost their lives by strangulation or beheading. Many historical sources tell of the terrible suffering inflicted on prisoners here and the horrifying nature of it. At present, the Carcer Tullianum is owned by the Vicariate of Rome and the Arciconfraternita di San Giuseppe dei Falegnami, and is managed by the Opera Romana Pellegrinaggi.