The Mamertino has two subterranean cells where Rome's enemies, most famously the Goth, Jugurtha, and the indomitable Gaul, Vercingetorix, were imprisoned and died, of either starvation or strangulation. In the lower cell, legend has it that St. Peter himself was held prisoner and that he miraculously brought forth a spring of water to baptize his jailers. A church, San Giuseppe dei Falegnami, now stands over the prison. A recent restoration of the cells installed a multimedia show, to mixed reviews. The automated tour focuses on the Christian history of the cell, and the audio is more fluffy than historical, making this stop a must-see only for those who really must see the place where Peter and Paul once (according to myth) stood.
Via del Tulliano, Rome, Latium, 00186, Italy