The Mirador del Monte Castle is at the end of the road that leads to the famous Cueva del Castillo, right at its entrance. From there's a panoramic view of the river Pas, Toranzo Valley and Puente Viesgo. One of the things that struck me was seeing hundreds of raptors flying over the valley. Monte Castillo (or Peak Castle) is a cone-shaped limestone mountain 355 meters above Puente Viesgo (1.5 km from the village). It got its name because it is where, in the eleventh century, a castle lookout existed that controlled Toranzo and Piélagos valleys, and called the "route shield" (important channel of communication with the plateau).