demonstrated by substantial remains of Roman walls and of composite concrete. It has a trapezoidal shape with the longest side facing away from the town in order to better face potential attacks. There are four corner towers, a gate tower and a keep where the garrison Tolentino had imposed on Urbisaglia resided. Indeed, the fortress's main function, other than to control the surrounding areas, was to guard the town and to prevent any rebellious acts from the citizens of Urbisaglia who resented Tolentino's power over them. Sources and references Bacchielli L., Ch. Delplace, W. Eck, L. Gasperini, G. Paci. Studi su Urbisaglia romana. Supplementi a PICUS. Tivoli, 1995. Giuseppe Ferranti. Guida al territorio di Urbisaglia. Pro Manoscritto a cura di Urbsalviambiente. Urbisaglia, 1994 Miria Salvucci, Giovanna Salvucci (et al. ). Urbisaglia. Urbs Salvia, Capolavori in corso. Urbisaglia, 2003. See also Archaeological Park of Urbs Salvia Rocca di Urbisaglia Abbey of Chiaravalle di Fiastra External links Comune di Urbisaglia - istitutional site TAU - Teatri Antichi Uniti Cities and towns in the Marche