Château de Quéribus is a ruined castle in the commune of Cucugnan. It is one of the 'Five Sons of Carcassonne', along with Aguilar, Peyrepertuse, Termes and Puilaurens: five castles strategically placed to defend the French border against the Spanish, until the border was moved in 1659.
Quéribus was first time mentioned in 1021 when it was one of the main Barcelonan strongholds north of the Pyrenees.
It is sometimes regarded as the last Cathar stronghold. After the fall of Montségur in 1244 surviving Cathars gathered together in another mountain-top stronghold on the border of Aragon. In 1255, a French army was dispatched to deal with these remaining Cathars, but they slipped away without a fight, probably to Aragon or Piedmont - both regions where Cathar beliefs were still common, and where the Occitan language was spoken.
Quéribus is high and isolated. It stands on top of the highest peak for miles around. In 1951 restoration work on the turret began, and between 1998-2002 a complete restoration of the castle was undertaken: the castle is now accessible to visitors.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.