Castle of Ars Monument · les Valls de Valira, Alt Urgell, Lleida Castle first mentioned in 1102, in an agreement between Guitard Caboet and Arnau Ramon de Castellbò; in 1110 Guillem Guitard de Caboet donated it to the chapter of Urgell. It was part of the defensive system on the left bank of the Valira. Of its precinct, mainly a rectangular tower of about 5 by 6 meters survives, today reduced to fragments up to 9 meters high. A Bien Cultural de Interés Nacional (Catalonia's top heritage-protection category). Photo: jordi domènech (CC BY-SA 3.0) What to see and do in les Valls de Valira