Château de Mauvezin, occupied since protohistory, was transformed into a castrum in the Middle Ages and later into a castle. The castle was built by Gaston Fébus (also Phoebus) around 1380. Following the merging of Bigorre into the Kingdom of France in 1607, it fell into disuse and was dismantled piece by piece, its stones being used for other buildings.
Today the castle is being restored and houses a historical and folk museum of Bearn and Bigorre.
The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.