Castle of Aínsa Monument · Aínsa-Sobrarbe, Sobrarbe, Huesca Castillo de Aínsa, in the Pyrenees, province of Huesca, whose remains — among them the Torre del Tenente — rise to the west of the Plaza Mayor, on the promontory where the town began, at the confluence of the ríos Cinca y Ara. Its origin dates back to the 11th century, when it formed part of the Christian defensive line that reached as far as Abizanda, and it became the core of the capital of the county of Sobrarbe, integrated first into the kingdom of Nájera-Pamplona and later into that of Aragón. In 1124 Alfonso I el Batallador granted the town its settlement charter under the fuero de Jaca. The importance of the stronghold also led to the nearby iglesia de Santa María being designed with defensive purposes, as shown by the arrow slits in its tower. The whole historic centre was declared Conjunto Histórico-Artístico (a heritage protection category for historic town centres, now part of the Bien de Interés Cultural) in 1965. Photo: Chuan (CC BY-SA 3.0 es) What to see and do in Aínsa-Sobrarbe