The Gulf of Morbihan is one of the great natural curiosities of Brittany — a vast tidal lagoon connected to the Atlantic by a narrow channel, scattered with around forty islands and hundreds of islets. The name means "little sea" in Breton, and it earns it: the gulf has its own microclimate, its own tides (different from the ocean outside), and a quality of light that artists have been painting for a century.
Boats leave from the port of Vannes for day trips to the two largest islands, the Île-aux-Moines and the Île d'Arz — both car-free, with sandy beaches, old farmhouses, and excellent cycling. Longer excursions go out past the prehistoric monuments of the Gavrinis cairn (a chambered tomb decorated with spirals that rival Newgrange) and around the full circuit of the gulf. Ferries run from spring through October; in summer you can also rent kayaks from the port and explore independently.