Here rises the Torre de las Arcas, one of the most distinctive towers in Úbeda’s medieval walls. This octagonal structure, rare within the city’s fortifications, is an albarrana tower built during the Muslim period and later modified in the fifteenth century. Its polygonal form, machicolations and visible stonecutters’ marks all point to its role as an advanced defensive post, protecting the Puerta del Castillón and controlling access to the city’s north-western entrance. The name “Torre de las Arcas” comes, according to some authors, from the administrative function of another now-lost tower where the municipal coffers were once kept. The tower you see here was originally known as “El Castillón”, but over time the names became confused. Whatever the origin, this tower remains a valuable example of Úbeda’s military architecture, part of a defensive system of which nearly 80 percent of the original layout still survives. Its presence in the middle of Calle Corredera de San Fernando is a reminder that the city, far from being only a commercial centre, was once a carefully organised stronghold designed to defend its gates and its Alcázar.