Gibraltar is a British Overseas Territory and headland, on Spain's south coast. It's ruled by the Rock of Gibraltar, a 426m-high limestone edge. First settled by the Moors in the Middle Ages and later administered by Spain, the station was surrendered to the British in 1713. Layers of strongholds incorporate the remaining parts of a fourteenth century Moorish Castle and the eighteenth century Great Siege Tunnels, which were extended in WWII.