Castell de Montoliu de Segarra is a 13th-century fortress located in the upper section of Montoliu de Segarra in Lleida's La Segarra region, featuring ruins significantly altered by later construction including a modern water tank. With documented origins tracing to 1077, the castle later passed to Santes Creus monastery in 1227 and remained under monastic control until the abolition of jurisdictional lordships in the 19th century. The site preserves remnants of medieval architectural traditions within the rugged Catalonian landscape.