From the V&A website:
The World Beach Project is a global art project open to anybody, anywhere, of any age. Building on the experience many of us have of making patterns on beaches and shorelines, this project combines the simplicity of making patterns with stones with the complexities of shape, size, colour, tone, composition, similarity and difference. It is really easy to join in – see the instructions below, or go straight to the map and see what others have been been doing. Why is it all about stones? Sue’s idea for this project has always been based around patterns made with stones. That means no seashells, seaweed, driftwood or other flotsam and jetsam commonly found on beaches. How it works: The project happens in two stages, in two locations: first, at a beach where you choose the stones and make your pattern, recording the work-in-progress with some photographs along the way. Then later, at a computer, you can upload the photographs to the V&A website to complete the project.