Castle of Rialb Monument · Rialp, Pallars Sobirà, Lleida Gothic castle documented since 1065 ("in castro Rialb"), significantly rebuilt in the 15th-16th centuries with slate stone and arrow-slit windows; already by the 17th century it was described as in ruins. Possibly an outpost of the castle of Surp, it was disputed among the Bellera family, the counts of Foix, and the Crown of Aragon, and in the 15th century it was the administrative center of one of the five quarters of the viscounty of Castellbò. Today it preserves two stretches of wall about 7 m high forming the northeast corner; it is owned by the Diputació de Lleida. A Bien Cultural de Interés Nacional (Catalonia's top heritage-protection category). Photo: Herodotptlomeu (CC BY-SA 4.0) What to see and do in Rialp