This 11th century castle was ordered to be built by Ferdinand I as a fortress in which to protect himself and the city. It lived through a time of great splendor in the Middle Ages, undergoing an important transformation in the 18th century to turn it into an artillery fort. It reopened its doors in August 2009, with a completely renewed image, both of the fortress and its defensive structures, as well as the surrounding gardens. Rhomboid in shape, it is made up of a series of concentric structures, a moat, a counterpit, a stone block, a residential body and an interior patio. The donjon stands out: the tallest, the last defensive stronghold of the fortress.