The only ancient access doorway left is located along the western side of the city walls.

Recently restored, it belongs to the Municipal Administration.
In the Middle Ages, access to the village was ensured by a drawbridge which was located to the right of the present entranceway.

Therefore, it was not exactly in axis with the main street.

To ensure a better protection for the drawbridge, a very thick rampart was added to the Cassero.
The Cassero (fortress) underwent several changes. It was build in the 14th century as an imposing square building with a mainly military function. In the 16th century, following the invention of long-range firearms, it was substantially modified. In the early 18th century, it still maintained its defensive role. Finally, in the second half of the 18th century and in the 19th century, it was transformed into an elegant access doorway. The secondary doorway and the drawbridge were demolished.
In 1807 a small tower with a clock and four bells was added. It also features allegorical statues representing the "Hours" and the "Seasons". Today, the Cassero is popularly called "Campanazzo" (big bell).