Castèl de Arcas (Château d'Arques) Aude, Languedoc (Occitanie), France.... www.catharcountry.info ... The Château d'Arques aka the Donjon d'Arques is often called a Cathar Castle, it was built not by Occitan Cathars but by French Crusaders. Pierre de Voisins’ son, Gilles, rebuilt the village of Arques as a bastide in 1268 and also started work on the present castle. It was completed by his son Gilles II in 1316. The word French donjon means castle keep.