Cantabria certainly can’t claim to have any spectacularly huge or impressive castles like its neighbours in Burgos and Palencia, but it does have a few modest offerings, some of which are visitable.
Tucked away above the village of Argüeso, off the CA183 at Paracuelles between Reinosa and Alto Campoo, this small restored castle has had a number of functions over the years. Currently it is fully and beautifully restored, with beautiful woodwork throughout its little maze of rooms. It’s open to the public, entry fee is 2€. It is set up as a temporary exhibition space, with different exhibitions every month or so, and is the occasional location of weddings and concerts in summer. In August there is an annual falconry weekend open to the public, and they also hold medieval mock up days. At all times there are good views from its roof over the village and valley. In the same village is the Poblado Cantabro (signposted from Reinosa), a good Mesón restaurant, a nice bar/posada, and several marked walks.
One of the attractions in the fishing town of San Vicente de la Barquera in the west of Cantabria, this castle stands proudly above the town, in the pretty old town. The castle is open to the public, and has a small entry fee, but the views from the top are well worth it. Built on top of a rock, it has views over the Picos in one direction, and the town and beaches beyond in the other. It is home to regular art and photography exhibitions. San Vicente also has the reminants of its old town walls, if you continue walking up through the old town to the church, where the old walls are in great condition. If you head down the path on the right hand side of the church, you will come to the estuary (this is a little rocky). Following round to the right here, you will climb up through the pine trees to a gate in the walls, and find yourself next to the pilgrims hostel (for the Camino de Santiago).
In the eastern town of Castro Urdiales is the third good example of a castle in Cantabria. Combining a castle and a lighthouse, this castle is located above the port, close to the impressive gothic church. It is now home to not only the lighthouse, but also to an exhibition space, open to the public.
In addition to these castles, there are many defensive towers, torres defensivas, all over Cantabria. These are often signposted in towns and villages with the pink tourist signs, but most are closed to the public, are private property, or are in ruins. A few which are restored and open to the public are (advisable to check opening times on the websites):
Torre de Pero Niño in Sovilla, near Los Corrales de Buelna. It contains an interpretation centre for the Middle Ages in Cantabria. It’s signposted off the new CA170 and adult entrance is 3€.
Torre del Infantado in the centre of Potes houses a cultural centre, a permanent art installation and has great views from the top of its 6 floors, as well as a central patio and an interesting mix of woodwork, steel and light throughout. Adult entry is 3€, closed Mondays.
Torre Don Borja in Santillana del Mar is now used as an exhibition space, workshop space and holds a paper market on the first Sunday of each month (in 2013). In summer they also run guided tours.
Torre del Pontón de Linares in the small village of Linares, above La Hermida in the gorge of the same name on the N621 to Potes. It has exhibitions of life in the Middle Ages and is not open all year round.
Torre de Estrada in the village of the same name, south of San Vicente de la Barquera, holds the permanent exhibition “Maquis, Realidad y Leyenda”, which tells the story of the Maquis, those who after the end of the Spanish civil war, continued the fight against Franco’s troops. Set over 2 floors of the tower and with a video with memories of those still able to tell their tales. Entry and optional guided tours are free, however it is only open 15th June – 30th September.