Pieces: 1000 Size: 30" x 24" Photographer: Peter Doran P/N: 40579 A hill or ridge of sand piled up by the wind is called a sand dune. Dunes may form wherever there is a lot of loose sand and enough wind to move it. Sand dunes are vital to the survival of beaches and protect homes and habitats further inshore from salt spray and sand.  This 1000 piece beach puzzle will provide hours of fun.