Worm's Head is a headland, at Rhossili, part of the City and County of Swansea, Wales. It is the furthest westerly point of the Gower Peninsula. The name Worm's Head is derived from an Old English word 'wyrm' for 'sea serpent'. The headland of carboniferous limestone comprises three islands: the Inner Head, the Middle Head which features a collapsed sea cave which is known as the Devil's Bridge, and the Outer Head. In total, it is approximately one mile long.