Frías Castle is the castle of the Dukes of Frías, located in Frías, overlooking the Tobalina valley. It was built between the 12th and 15th century.
Wikipedia https://en.wikipedia.org/wiki/Frias_Castle
Address 17 Calle del Castillo, Frías 09211, Spain
Coordinates 42°45'44.103" N -3°17'42.581" E
