You are standing before the oldest structure in the entire castle: the Keep. Of Muslim origin, it was likely built in the ninth and tenth centuries using river pebbles arranged in a herringbone pattern, bound together with stone ashlar.
This tower served as the final refuge for the castle's defenders in the event of an attack. During the most recent restoration, the double-arched mullioned windows at the top were reconstructed on two of its facades, following an ancient engraving of the tower. The original entrance to the building was located high up on its western side to make access difficult for attackers.
Inside, you will find an interesting exhibition featuring reproductions of ancient plans and prints of the castle. There is also a collection of pottery, glass, and other artifacts recovered during various archaeological campaigns. Most of these pieces were found in the remains of the old Church of San Juan on the southern slope of the castle, as well as in this very tower.
The collection includes ceramics of various origins, glassware, bullets, and metal pieces dating from the modern era.