Worm's Head promontory, Wales. These grassy, limestone cliffs form the end of the Worm's Head promontory, a spur of rock jutting out into the Bristol Channel from Rhossili Bay, on the Gower Peninsula, South Wales. The promontory is over a kilometre long and rises some 45 metres above the sea. These limestone cliffs date from the Carboniferous period some 360-300 million years ago. The Gower Peninsula was designated an Area of Outstanding Natural Beauty in 1956, and is famous for its spectacular coastline.