Castle of la Concepción Monument · Cartagena, Campo de Cartagena, Murcia Medieval fortress of the 13th-14th centuries built on the remains of a 12th-century Muslim alcazar, on one of the five hills that historically protected Cartagena, with panoramic views over the Roman theatre, the harbour and the whole bay. After the city's conquest in 1245 by the then infante Alfonso X the Wise, he ordered it fortified, raising the castle at the highest point, replacing the old alcazaba, of which the lantern that served as a lighthouse is still preserved. The castle, which shares stonemasons' marks with those of Aledo and Lorca, was left unfinished after the dissolution of the Order of Santa María de España, founded in Cartagena by Alfonso X for the naval struggle against the Muslims and dissolved after losing almost its entire fleet. Photo: Rafa Esteve (CC BY-SA 4.0) What to see and do in Cartagena