The Atalaya Castle (eighteenth century) is one of the military fortifications that were part of the defense of Cartagena. The defensive system of the period was composed of an important walled enclosure, which surrounded the city, the arsenal, and a group of fortresses outside the city wall, located on the nearby hills. One of these defensive constructions is the Atalaya Castle or Fort, located to the west of the city from its position it protected the population from attacks both by land and by sea. To the north and west by land, through the Almarjal and the Pelayo mountains, the south by sea covered the possible landings in the bays of the Algameca Grande and the Algameca Chica. The building is a magnificently construction, the fort has a pentagon ground plan with five bastions at each angle. It has an interior building in U arranged on a solid bastioned platform the whole complex is surrounded by a dry moat. The fortification present certain formal elements used in other constructions that had been lifted in the city at that time, circumstance gave unity to the whole. The materials consisted of employed mainly stone and brick, the constructive elements introduce certain heterogeneity. The purpose of the communication is to present the results of the comprehensive analysis carried out in the Atalaya Castle as well as to contribute, through its dissemination to raise awareness of the need for its restoration and enhancement. Research has studied the characteristics of the formal and constructive system of the fortification currently in a state of semiabandonment, a proposal has also been conducted for a new cultural use as a guarantee of its correct recovery and conservation.