Located on the "Corbières Fenouillèdes" regional natural park western edge, the Coustaussa castle was in the Middle Ages an important stronghold which commanded the road from the Haute Vallée de l'Aude to the Corbières.

With an influence as important as the castles of Termes or Puivert, it was, militarily speaking, an obligatory crossing point for the Crusade against the Albigeois.

Medieval castle in Cathar country, it still has rare monumental remains from the time of the Cathars.