After the Napoleonic Wars, at the beginning of the 19^th  century (1808–1814), the Citadel  was practically abandoned, as its fortress-like design was no longer suited to the new methods  of warfare. However, in 1827, a small fort  was built in the old Sant Joan  bastion with the aim of placing a battery to defend the coast. It is a quadrangular enclosure that partially incorporates  the old walls of the fortress and even includes  one of the old towers of the medieval wall. The fort  is equipped with a series of arrow slits , an obsolete  type of window  at that time—when bows or crossbows had not been used for centuries—but which must have been used to ventilate the interior space.

Internally, the fort  was composed of a series of elongated compartments, arranged radially, of which currently only one preserves the barrel-vault covering. Although it seems that it was initially planned to have two floors, the  small fort was never completely finished.