The castle of Castro del Rio, known locally as Castillo de Castro del Rio, is located in the centre of the village of the same name. The village of Castro del Rio already existed in Roman times when it was known as Postumianus Castra, Castra Soricaria or Castra Julia. In Moorish times the town was called Qasida or Qasrut and described as a 'strong'. In the 11th century the town fell under the rule of the Taifa of Granada. In the 12th century, under the rule of the Almohads, a walled medina was built. The castle was part of and situated on a corner of the city walls and probably dates from this time. In 1232 the town was conquered by Saint Ferdinand III, King of Castile. He used this border fortress as a stronghold against recurring Moorish attacks. In 1565 the town and castle of Castro del Rio were sold to the Marquis of Priego. It remained the property of the Marquis until the reign of Ferdinand VI, King of Spain, in the mid-18th century. The current ruins of the Castro del Río castle look very dilapidated. The interior of the castle cannot be visited.