Arcos de Jalón Castle, dating from the 14th century, stands on the site of an old Arab fortress. It was besieged in the 14th century by the supporters of the Castilian King Pedro I, who fought against the rebel D. Fernán Gómez de Albornoz, supporter of his bastard brother Enrique de Trastamara.
This castle has a rectangular floor plan although it is quite irregular due to the fact that it adapts to the rugged land of a high and narrow hill that divides the town into two parts. A robust keep is attached to the castle walls which are made of thick stonework, horizontal brick rows and ashlar with stonecutter’s marks on the corners. There is only one entrance which is located high up and two loophole windows.
Inside there are remains of the structures that divided the tower, which once was taller, into different floors, and all throughout the perimeter, you can see where the foundation walls began and some towers that reinforced the structure.
This fortress is so unique due to the double-lined brick walls, a technique that mainly had a structural purpose, but has also given the castle beautiful reddish lines between the stonework. This construction method has a clear Mudejar origin which was most likely influenced by the amount of Muslims in the village and in the area of Aragon.
References:Doune Castle was originally built in the thirteenth century, then probably damaged in the Scottish Wars of Independence, before being rebuilt in its present form in the late 14th century by Robert Stewart, Duke of Albany (c. 1340–1420), the son of King Robert II of Scots, and Regent of Scotland from 1388 until his death. Duke Robert"s stronghold has survived relatively unchanged and complete, and the whole castle was traditionally thought of as the result of a single period of construction at this time. The castle passed to the crown in 1425, when Albany"s son was executed, and was used as a royal hunting lodge and dower house.
In the later 16th century, Doune became the property of the Earls of Moray. The castle saw military action during the Wars of the Three Kingdoms and Glencairn"s rising in the mid-17th century, and during the Jacobite risings of the late 17th century and 18th century.