Dénia's castle crowns the city. An Arabic structure, due to the fact that the locality was a head of the Arabic kingdom of ‘taifas’, it is mixed with both a great number of later styles and former Roman vestiges. In the oriental part of Castle (Torre de Galliner) there are recognised remains of structures from Roman times.

It is one of the elements that defines the historical topography of the urban core. On its slopes have been discovered remains of houses and fortifications of the Roman Diannium.

At present it has been rehabilitated and prepared for the tourist visits. From the highest point there is a magnificent panoramic view of the local area. It is the setting for numerous cultural events. In its interior is situated the Archaeological Museum of the city.