Overview

In 1483, as ordered by Cardinal Giuliano della Rovere, Bishop of Ostia and future Pontiff Julius II, the construction of Ostia Castle was begun, designed by the Florentine architect Baccio Pontelli, and finished after three years, during the reign of Pope Innocent VIII. This Renaissance building incorporated a circular tower ordered by Pope Martin V in 1423-1424 for the protection of the medieval village. A papal customs office was also founded in the fortress, which was responsible for collecting taxes on incoming maritime trade to Rome. In the 16th century, Julius II carried out major transformations: he created a papal residence on the western side, renovating parts of the building, and commissioned a monumental staircase, frescoed by Baldassare Peruzzi, with mythological scenes related to the myth of Hercules. The 1557 flood, which changed the course of the Tiber at the castle, and the formation of dense marshes near the building caused the village and the fortress itself to be abandoned. In the 19th century, the latter became a prison for condemned forced labourers, who were also employed as the workforce for archaeological excavations in the ancient city of Ostia. At present, the monumental complex consists of a perimeter circuit of casemates (i.e. gun chambers), three towers (one of which is the tower of Martin V) and a moat.