This fort is one of the many military fortifications scattered along the Tunisian coast to defend the coastline. The borj – bastion – was built in 893. In around 1463 it was considerably extended to serve as the residence of the city governor as well. At the end of the XVIth century, it was substantially modified and adapted to accommodate firearms. The monument was turned into barracks after the establishment of the French protectorate over Tunisian in 1881.

As it stands, the citadel is a deformed square of 50m with a salient at each corner. A single door leads into it through a double elbowed corridor. The courtyard is bordered with cells that were used as prisons and storerooms; Sidi Bouali’s mausoleum, a late XVth century warrior-monk, stands in the middle.