Queribus 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. 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 (the present border between the Aude and the Pyrénées-Orientales). It is at coordinates and an altitude of 728 m. The nearest village is Maury, Pyrénées-Orientales (population 1000).