On the route of the *bastides* (fortified towns) and *castelnaux* (castle-centered villages) leading from Auch to Marciac, be sure to stop at the Donjon (keep) of Bassoues. Located in the Astarac region, in the heart of the *bastide* of Bassoues, this 14th-century masterpiece of military architecture—visible from afar—is truly striking. Rising 43 meters above the *bastide*, the keep features both defensive and residential elements, including elegant Gothic chambers and a spiral staircase of 197 steps that leads to the top platform, which is crowned by a magnificent set of machicolations. Notable for the quality of its construction (using local stone), the meticulous attention to detail (such as dripstones and moldings marking the various levels), and the comfort of its interior spaces (equipped with latrines, fireplaces, and stone sinks), it stands as one of the best-preserved keeps in the southwest of France. Climb to the very top—all 43 meters—and you will be rewarded with a grand panorama of the countryside, the rolling hills of the southern Gers, and the Pyrenees mountain range. Also worth seeing are the village ramparts, the covered market hall, the arcaded walkways, the Church of the Nativity, and the Basilica of Saint-Fris.