The Château des Tours was built in the 14th century. At that time it had three towers: one had a polygonal interior and was the dungeon, and the others were circular flanking an oblong building on the east and west corners of its south face; then, at the same corners on the north face, there are sentry boxes with Corbels. The oldest part is in the south of the present castle and is also a little higher.
North of the original castle there was a courtyard formed by the castle and crenellated walls outside with wide and deep ditches below. These ditches remain but the walls were replaced in the 16th century by rectangular buildings. At the east and west corners of the north facade there are two round towers, less high than the others, but topped like them with machicolations. There is a door between these two towers above which are the Arms of Calvimont carved on a large stone: they have lain since 1793 a few steps in front of the door.
The castle was restored by Viollet-le-Duc in the 19th century.
References: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.