The Castle stands on the summit of the hill, in the highest and most panoramic areas of the city. The structure has peculiar characteristics of Aragonese architecture and can be dated between the XI and XII centuries. With almost trapezoidal shape, it has sides of different size and towers arranged at the four corners. Each tower is articulated inside with some rooms of varying size. Bereavement and earthquakes have accentuated the degradation from the sixteenth century, so that in the nineteenth century original building will remain the Torrions, part of the city walls and a few other buildings nowadays immersed in the green of the Civic Garden. The complex has been the object of a long restoration period.