Anse Source d'Argent is the island's signature beach — a series of coves sheltered by enormous pink granite boulders, with shallow, warm water and a scattering of palms. Access is through L'Union Estate (there is an admission fee, which covers the estate grounds too). The beach is best in the morning before the day-trippers arrive; by early afternoon the main coves can be busy.
The water here is shallow and calm, good for swimming and snorkelling. Stronger swimmers can venture beyond the boulders to where the coral begins.