Castillo de Aguilar is known from at least the 9th century. It is mostly in ruin, a part turned into a cistern for the local aqueduct. In the 9th century Aguilar de la Frontera became the headquarters of the rebel Umar ibn Hafsun, who built extensive fortifications and reinforced the castle. However, in 891, Umar ibn Hafsun lost the town to emir Abdallah ibn Muhammad of Córdoba. Due to its strategic position, it was contested and, after the dissolution of the caliphate of Córdoba, it became part of the cora of Cabra.
In 1240 it was conquered by the Christians, although numerous Muslims were allowed to remain. King Peter I of Castile assigned its seigniory to Alfonso Fernandez Coronel, but later reannexed it to the crown. The town was renamed Aguilar of the Frontier due to its position on the border with the Moorish Kingdom of Granada.
Since the mid-seventeenth century the castle was no longer needed for defense, consequently in 1860 it was converted into a Hospital. The Lisbon earthquake in 1755 caused part of the building to collapse. The fallen stones were reused for various public and private works. The remains of the castle are located on the hill to the north of the town on the extension of Calle Villa. The Tourist office is located at the castle. Free guided tours available on request.
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.