Located in the northeastern corner of the walled city, the Rocca was designed by architect Matteo Nuti at the behest of Sigismondo I Malatesta. Work presumably began in 1438. Within the complex, which has a quadrangular plan with scarp walls protected by a moat, there were additional defensive structures: the Rocchetta and the Mastio, which were mined and destroyed in 1944. Tunnels and secret passages underground connected the fortress with the outside. Upon entering, one can see today a vast lawn courtyard, the cells and chapel in the lower eastern building, and a room now used as an exhibition hall accessed by the characteristic brick ramp.
