The Mamertine Prison, in antiquity the Tullianum, was a prison with a dungeon located in the Comitium in ancient Rome. It is said to have been built in the 7th century BC and was situated on the northeastern slope of the Capitoline Hill, facing the Curia and the imperial forums of Nerva, Vespasian, and Augustus. Located between it and the Tabularium were the Gemonian stairs leading to the Arx of the Capitoline. The church of San Giuseppe dei Falegnami now stands above the Mamertine.