Torre del Oro is a distinctive defensive tower built on the Guadalquivir River's left bank in Seville between 1220 and 1221 during the Almohad period. Standing 36 meters tall with a striking dodecagonal design, its three distinct sections reflect different historical eras: the original Almohad stone structure, a narrower 14th-century addition, and a cylindrical section topped with a golden dome added in 1760. Despite popular legend, the tower's golden appearance derives from a mortar coating that reflects light off the water rather than stored American gold. Today it houses a Naval Museum and offers visitor access to its upper terrace with river views, operating daily with nominal admission.