The first medieval enclosing walls date back to the 13th century. In the following century, the “muro dell’Ala” is built to attach the Cassero to the external walls, so enlarging them. About halfway through the 1300s, the Perugians, owners of the dwellings, brought about other changes. During the 1600s, the walls and towers were demolished.
The main entrance to the historical centre is through Porta Fiorentina, part of the enclosing wall in the 1200s. What we see today, is the result of an 1813 reconstruction: outside there is a pre-door, to its left are the remains of the Medici coat of arms; inside, the door has three arches above which there is a nook with S. Michele, the patron saint of the city. On the left, the walls bend towards S. Francesco. The walls here are called “Pisane” due to the participation of the Republic of Pisa in their construction. The outside corresponds to Garibaldi Square and along this whole section, traces from other towers can be seen. Carrying on towards the current Porta S. Giuliano, the walls descend to enclose the ecclesiastical complex of the Collegiate and then continue towards Porta Romana, i.e. the 1300s Porta di S. Angelo. Above this last door, is a nook with a terracotta statue of S. Michele. Going ahead, the Municipal Theatre is against the walls.