The construction of this opera was begun in 1820 and ended around 1825, its goal was to protect the surrounding area of San Bernardino. It is near the Quezzi tower and Monteratti.Access to the interior was possible only through the covered walkway, built after 1826. This was situated at the antistant door of San Bernardino. This tunnel, today "lends itself" well to the stories that it is a secret passage that leads towards the city walls or to who-knows-where.The tower is made-up of an underground room (besdie which there is a cistern), the ground floor, and the top floor. On this, one of the original cannons is present with its openable grate, and is still in working order.