Rhossili Bay, Swansea, has been voted TripAdvisor's 9th best beach in the world!  Last the year, it ranked 10th in the world.

“Truly the most beautiful beach. The sheer scale and wildness of the location add to the majesty.”

To see the full list: 

http://www.tripadvisor.co.uk/TravelersChoice-Beaches-cTop-g1-a_Mode.expanded