The castle at Frias overlooks the village from its rocky outcrop above and forms part of a fortified ensemble that incorporates the village and the fortified bridge crossing the river Ebro far below. The main keep or torre del homenaje is situated on a spectacular rock pinnacle towering above the main street of Frias and forms one of the most dramatic castle sites in Castile. Although of 10th century origin, the present structure has the earliest masonry dating to the 12th century. Further developments and modification have taken place within the castle in subsequent centuries so the castle as we find it today is an amalgamation of building phases from 12thC to the 16thC. The entrance to the castle is obtained from the market square within the walled precincts of the town across a wide rock-cut ditch by means of a drawbridge. Once across the bridge the visitor has to negotiate the well defended entrance door and into the Patio de Armas or main bailey of the castle.