The Church of Saint-Pierre (Église Saint-Pierre) was built in the early 13th and the construction continued until the 16th century. The spire was destroyed in 1944, and has since been rebuilt. The eastern apse of the church was built by Hector Sohier between 1518 and 1545. The interior choir and the exterior apse display an architecture that embodies the transition from Gothic to Renaissance.
Until around the mid 19th century, the eastern end of the church faced onto a canal that was then covered and replaced by a road. Various artists and engravers recorded this relation of the church to the canal; for instance, the Scottish painter David Roberts made several very similar views, one of which (dated to c.1830) is in Musée des Beaux-Arts in the Château de Caen.
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.