Pagax Castle is located in the former province of Rouergue and the limit of Quercy nearby. It overlooks the valley of the Lot on the heights of the village of Flagnac in Aveyron.
Its architecture is typical of the fortresses of the 12th and 13th century, with a main building of square plan high on three floors above a ground floor blind, flanked by four towers connected by battlements.
The earliest definite mention of the castle dates back to 1259 Pagax. It was erected to secure the royal authority in the region. He also belonged to the noble and powerful family Montarnal From then and then passed through inheritance in the family of Moret. This became very important in the Rouergue and near Gevaudan and was known for his vast possessions, for his services and military posts, distinguished by its alliances which gave him kinship with the first houses of the kingdom.