The site of Quéribus reveals the organization of a significant fortress that has been regularly modified and adapted to military requirements. Therefore, the citadel today displays elements linked to the Middle Ages entangled with fragments from the Renaissance. Access to the fortress is via a chicane staircase that leads to a real trap where three successive walls in staggered rows rise. To prevent the entry of a potential assailant, the mouths of the loopholes and gun ports open on all sides. The fortress of Quéribus served as a refuge for heretics and faydits lords (lords dispossessed for their support of the Cathars) long after the end of the Albigensian Crusade, until the capture of Chabert de Barbaira who finally agreed to surrender Quéribus in exchange for his freedom.