The Castle of Los Duques de Frías overlooks the vast valley of Tobalina. It has parted windows and preserves three mullioned windows with Romanesque capitals dating from the 13th century, representing warriors on horseback and fantastic birds.
It consists of a tower of homage and an irregular courtyard, plus a moat and turrets in the corners. After being rebuilt by Alfonso III in the 15th century, it was handed to the Fernández de Velasco family.
The castle has round turrets separating the
castle from the rest of the wall. The square tower protects one
gate, the moat and the barrier.