The city then, as now, was girdled by strong walls. The gates were twelve in number. Those not turned towards the river were strongly fortified with towers and bastions. The farther bank of the Guadalquivir was defended by castles and redoubts. Upwards of a hundred keeps and watch-towers studded the adjacent country. One of the most vital points in the defensive works was the poetically-named Torre del Oro (tower of gold), which still exists, and is familiar to every visitor to the city. The tower is a twelve-sided polygon of three storeys. It is surmounted by a smaller tower, also of twelve sides, which in turn supports a small round cupola. This superstructure was added in the eighteenth century, whereas the main building was erected by the Almohade governor Abu-l-Ala in the year 1220. The tower was in those days connected with the walls of the city by what is called in military parlance a curtain, which was pulled down as late as in 1821. The outwork faced another watch-tower on the opposite bank of the river, and a great iron chain was drawn from the one to the other, effectually closing the harbour against hostile vessels. The assaults of the foeman and the deadlier ravages of time have stripped this strong and graceful monument of the beautiful tiles or _azulejos_ with which it was once adorned, and which seemed to have earned for it its present name. No Danaë, alas! waits in this tower of gold to-day for tyrant or deliverer. The place is occupied by clerks, whose pens are ever busy recording the shipments of coal brought by incoming steamers; and the immediate vicinity is infested by “tramp” sailors of all nationalities, mostly British, for whose benefit, presumably, rum, “Old Tom,” and other stimulating but unromantic beverages are dispensed at kiosks and bars. The spot appears to have been the scene of a picturesque episode recounted by Contreras. It is worth repeating as revealing the polished character of the dusky amirs who ruled in Ishbiliyah three hundred years before Charles of Orleans devoted his declining years, in his palace by the Loire, to the making of ballads, triolets, and rondeaux. The Abbadite amir, Mut’adid-billah, was walking one day in the field of Marchab Afida, on the banks of the Guadalquivir, and observed the breeze ruffling the surface of the water. He improvised the line-- “The breeze makes of the water a cuirass”-- and turning to the poet Aben Amr, called upon him to complete the verse. While the laureate was still in the throes of poetical parturition, a young girl of the people who happened to be standing by, anticipated him, and gave utterance to these original lines-- “A cuirass strong, magnificent for combat, As if the water had been frozen truly.”