Built between 1483 and 1487 during the pontificate of Sisto IV, Cardinal Giuliano of the Rovere (future Pope Giulio II) financed the construction of the Castle and entrusted the work to architect fiorentino Baccio Pontelli (registration on the portale of access to the courtyard). The architectonic complex constituted from a perimetrale system of casemates, that joined together three towers, the main one which was the previous tower from Pope Martino V, one rivellino and a wide surrounding ditch. The triangular shape of the Rocca was dictated by its primary function as defense of the Tevere (Tiber) river
Days of closing: Closed Mondays and in the days 1 January, 1 May, 25 December.
Timetable: Tuesday - h. 09,00-12,45, closes one hour within the h.13, 30.
Thursday also from the h. 14,30 to the h. 16,15, closes one hour within the h.17, 00.