www.oleron-island.com. Toll bridge 6 km W of Marennes, 30 km S of Rochefort. Between Royan and Rochefort, France’s second largest island (after Corsica) is celebrated for its oysters and miles of sandy beaches. The first sizeable town over the bridge is Le Château, with an old fortress once owned by the Dukes of Aquitaine and remodelled by Vauban. Along the east coast, a patchwork of marshland and glittering pools edge more oyster parks, and there are numerous small hamlets and fishing villages reaching north to the main town of Saint-Pierre. The best beaches are in the north-east, such as sheltered Boyardville, which also has a pretty port. Bird lovers should make for the Marais aux Oiseaux, a bird reserve-cum-breeding and rescue centre (off the D126 W of Saint-Pierre).