During the Middle Ages, the cities of Northern Italy were in a state of constant competition to control as much territory as they could. This was especially true during the wars of the communes of the 13th century, and city walls were erected to protect numerous towns during this period. Though many of those walls have crumbled, the walls around historic Cittadella still stand.

The town of Cittadella was founded in a strategic position halfway between the rival cities of Treviso and Vicenza. The very name of the town is the Italian word for citadel, as the city was founded to be a fortification. The imposing walls are 14 to 16 meters (46 to 52 feet) tall, and are in the shape of an irregular ellipse and surrounded by a moat. The only openings were originally the four city gates, Porte Bassanesi to the north, Porte Trevigiane to the east, Porte Padovane to the south and Porte Vicentine to the west, all taking their names from the cities they are facing.

The walls remain almost completely intact to this day, except for a stretch that was destroyed in the 16th century during the War of the League of Cambrai. The destroyed part and other damaged areas have been restored, and are now the only city walls in Europe where one can walk the full perimeter and retrace the entire parapet walkway.