site chosen was a site outside the walled enclosure and very close to the Guadalquivir River, in the area between Torre del Oro, Torre de la Plata, the Postigo del Carbón gate and the Postigo del Aceite gate. For this reason, in the neighborhood of El Arenal 17 naves from brick factory were erected perpendicular to the Guadalquivir and in front of the Almohad walls of the city, covering about 15,000 square meters. The Atarazanas also included the so-called Resolana del Río, a large expanse of sand that reached the Guadalquivir. It was one of the largest industrial installations of the Late Middle Ages in Europe, of an extension comparable to that at that time by the Venetian Arsenal. Architecturally it is a Gothic work and Mudéjar built all of it in a brick factory, which shows the influence of Almohad art in medieval constructions in the city of Seville. Astonish the dimensions of its wide and long naves attached and covered by vaults of edge, appropriate for the construction of the largest ships of the time. These naves communicate laterally through thick arches that are slightly pointed and facing each other, which start directly from the ground, and that together provoke attractive prospects inside. Operation In 1253 there were already ten galleys built and King Alfonso appointed ten captains or commissars, some of them French and Italians who had come to collaborate in the Reconquista. The commissars and their heirs had to take care of and repair the galley that was delivered to them and always use it in the name of the king and under the dependence of the Major Admiral of Castile (a position created by Alfonso in 1254). In 1407, reigning John II of Castile, in Seville there were already 70 commissars. The Major Admiral of Castile also had voice and vote in the municipal council. Besides as a shipyard, the Crown used the Shipyards for other functions since its first centuries of operation. Because of their large size, they served to host assemblies and public celebrations. They were also a natural place to store the booty and the prisoners captured by the fleets of the Castilian kings. Sometimes they served as jails for the social elite, for example for the nobles related to the king Peter of Castile after the victory of his rival Henry II of Castile. The Shipyards were able to build frequently