Castle of Alta-riba Monument · Estaràs, Segarra, Lleida The castle of Alta-riba is a ruined fortress of Estaràs (Segarra), declared a Bien Cultural de Interés Nacional (Catalonia's highest level of heritage protection), raised on the Tossal d'Alta-riba, above the small valley of the Malacara stream, a tributary of the Sió river. Its origins go back to the 11th century, when the county of Berga undertook the reconquest of the Sió valley; in the middle of that century Count Ramon Berenguer I granted the castle, with its tower and the surrounding houses, to a certain Bonfill. In the 12th century the Alta-riba lineage appears, first as castellans and later as lords of the place; in 1238 Berenguera d'Alta-riba sold the castle to the monastery of Santes Creus, which held the lordship until the abolition of lordships in the 19th century. It preserves a circular tower about five metres in diameter, built directly on the rock. Photo: Angela Llop (CC BY-SA 2.0) What to see and do in Estaràs