Basilica of Santa Lucia Extra moenia is a Byzantine church built (after Norman rebuilt), according to tradition, in the same place of the martyrdom of the saint in 303 AD. The current appearance is from the 15th–16th centuries. The most ancient parts still preserved include the portal, the three half-circular apses and the first two orders of the belfry. Under the church are the Catacombs of St. Lucy. For this church Caravaggio painted the Burial of St. Lucy, now housed in the Church of Santa Lucìa alla Badìa.
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.