There are four small castles each built on a large 300 m high rocky ridge. The castles were built to control the access to Montagne Noire and the Cabardes region. These are some of the few original Cathar castles left.
Cabaret castle is the main citadel with a barbican defence system. It consists of a north tower, a polygonal keep in the south and a group of residential buildings in the centre. The whole is surrounded by ramparts with a round walk. The crenellated wall is built with irregular material, with large stones forming the corners and openings.
The Tour Régine, closest to Cabaret, (Régine Tower) is the most recent fortress and the smallest. It consists of a round tower, surrounded by a small curtain wall which has collapsed. Below ground, the tower contains the largest cistern of the four castles. The tower has three storeys and is flanked by a spiral staircase. The white limestone used is identical to that at Cabaret. It is thought that this tower was built after the Albigensian Crusade: the name (Régine = Royal) suggests as much and there is no written evidence of its existence prior to 1260.
Also called Fleur-Espine (Thornflower), this castle is the least preserved of the four. On the highest part of the site, it consists of a square tower, a house and a cistern. A rectangular curtain wall gives protection. It is noted for the rarity of its murder holes and its four semicircular arched windows.
The Quertinheux castle is furthest south along the crest on an isolated rocky outcrop. It consists of a circular tower and a polygonal curtain wall. A chicane defends the entrance. It overlooks the remains of a destroyed Romanesque church.