The surrounding walls of the municipality date back to the beginning of the 1400s.
Most of the work was carried out by Lombard workers in 1437, the same period in which the three Entrance Gates were built: Cerreto Gate, Saint John’s Gate and Holy Cross Gate.
The Cerreto Gate, now called Diaz Gate, is set back from the steep sloping castle walls and it has a central brattice, an abutment tower and reconstructed battlements.
Saint John’s Gate, or the “Pesa” Gate, is at the end of the flight of stairs in Via Roma and it was the ancient entrance into the historical town centre.
The Holy Cross Gate, or Saint Nicolò’s Gate, now called Cesare Battisti Gate, was the only drawbridge and today you can still see the crenellated ramparts with slits for shooting and rooms for accommodating the lateral bombardiers.