The remains of the Castle can be visited
Château de Quéribus

The Château de Quéribus is a castle ruin on a rock in the Corbières mountains of French Occitania. Once a Cathar castle and later a French border fortress.
History+
The first mention of Quéribus Castle dates back to 1020, when it belonged to the County of Besalú and later to Barcelona. By the end of the 12th century, it came into the possession of the Cucugnan family, who were sympathetic to the Cathars. During the Albigensian Crusade, the fortress offered refuge to numerous Cathars, including Bishop Benoît de Termes. In 1239, Aragon sold the castle to the French King Louis IX. However, it was only after a long siege by Olivier de Termes that the castle finally fell to France in 1255, having held out eleven years longer than Montségur.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Hervé Rebours
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 42.8368, 2.6216