The kasbah rises above the old town on a low bluff, its thick walls built by the Ottomans in the 16th century on foundations that likely go back further. From the outside it reads as a solid, slightly severe fortification — large dressed stones, corner towers, a gate that once controlled the approach to the medina below. The Ottomans built it to anchor their hold on the interior routes, and the position makes the strategic logic clear: from the walls, you can see the valley approaches and the older town spreading out beneath you.
Inside, the kasbah is not extensively fitted out for tourism, which in practice means you get to walk through it without much mediation — the spaces are large, the masonry impressive, and the views from the upper portions of the walls across the medina and toward the distant hills are the best elevated perspective you will find in Gafsa. The Roman pools are visible below, which gives a sense of the layering: the springs that fed the baths, the medina that grew around them, and the Ottoman fort built to watch over all of it.