Château d'Usson

The Château d'Usson (en Occitan: Castèl de So) is one of the so-called Cathar castles in what is now southwestern France.

The castle dates from the 11th century (perhaps earlier) and during the Cathar period marked the eastern boundary of the territories of the Counts of Foix.

Before the défilé was cut through the mountains to link Quillan to Axat, this was an inaccessible outpost providing succour for faidits and other persecuted Cathars.

The seigneurs of Usson, Bernard d'Alion, lord of the Château de Montaillou, and his brother Arnaud d'Usson sent arms and supplies to their besieged comrades there.

[1] On display at the castle are parts of the wreckage of a Second World War British Dakota transport aircraft which crashed on 5 December 1944 on a nearby mountain with the loss of seventeen lives.