The sheltered eastern coast of Île d'Oléron, facing the mainland, is lined with oyster farms. At low tide, the beds are exposed — a strange low landscape of wooden poles and mesh cages stretching across the mudflats. The port of La Cayenne near Saint-Pierre-d'Oléron is the main oyster harbour, where producers sell direct from small huts along the quay.
Buying oysters here — typically a dozen for a few euros, opened on the spot, eaten with bread and lemon at a plastic table beside the water — is one of the definitive Oléron experiences. The season runs year-round (avoid months without an 'r' in French is the old rule, though modern refrigeration makes this less critical) and the quality is consistently high. The eastern port villages of Le Château-d'Oléron and Saint-Trojan-les-Bains also have oyster sellers.