Castle of Boltaña Monument · Boltaña, Sobrarbe, Huesca The castillo de Boltaña, declared Bien de Interés Cultural (Spain's highest level of heritage protection) in 2006, stands above the historic centre of the town. It was built in the 9th century by the Saracens of Sobrarbe to defend the valle del Ara against the Christians during the Reconquest; in the year 941 the town passed into the hands of King García Sánchez I de Pamplona. Between the 11th and 12th centuries, Boltaña gradually lost strategic importance in favour of Aínsa, to which Alfonso I granted a fuero in 1124. Of the fortress there remain sections of the pentagonal wall, a tower hexagonal on the outside and square inside, now badly deteriorated, a vaulted entrance gate and two arrow slits on the east and south faces, all built in ashlar masonry. Photo: agracier - NO VIEWS (CC BY-SA 3.0) What to see and do in Boltaña