Castle of el Catllar Monument · el Catllar, Tarragonès, Tarragona Castle raised in the upper part of the town, on a bend of the Gaià river, with documentary origins in the 11th century, though archaeological excavations point to a Muslim or even earlier origin. It belonged to the Montoliu family until the mid-14th century, then to the Requesens and Olzinelles families, and from the 15th century to the Queralt family until the 19th-century abolition of the lordships. The fortified complex, mostly from the 13th century, preserves part of the wall adapted to the terrain and two rectangular towers with arrow slits. Since 2002 it has been municipally owned and houses the Interpretation Center of the Castles of the Baix Gaià. A Bien Cultural de Interés Nacional (Catalonia's top heritage-protection category). Photo: lluis_tgn (CC BY-SA 3.0) What to see and do in el Catllar