The Gulf of Morbihan is a small sea, mor bihan in Breton, almost closed off from the Atlantic by a narrow gap at the entrance, and filled with islands: some say there are as many as there are days in the year, though the count depends on the tide. Water pours in and out through the narrows with such force that the current can run at several knots, and the shores are a patchwork of oyster beds, salt marshes and little harbours. The points where rivers meet the gulf, like this one, are lively places, full of birds, and shaped by the tides.
The prehistoric monuments are the other big attraction. This part of Brittany is rich in megaliths, and the cairn of Gavrinis, on an island in the gulf, has walls carved with swirling patterns that are over five thousand years old. Carnac, with its famous alignments of standing stones, lies a short ride to the north-west. The rides that start here often pass through both worlds, sea and stone.
The roads on the Rhuys peninsula, where Arzon and Larmor-Baden lie, are flat, quiet and pleasant, with views of the water from time to time and small villages of low white houses with grey slate roofs. Wind from the Atlantic is constant, and it can bring sudden showers, followed by bright light. Spring and early autumn are the best seasons, when the crowds have gone and the oysters are good.
Arzon, with about two thousand people, and Larmor-Baden have shops and cafes, but for fuel and a bigger choice, aim for Vannes, which is on the north side of the gulf and has a fine old town with medieval walls and half-timbered houses. Eat oysters and mussels, followed by a crêpe or a galette of buckwheat, with a bowl of the local cider. Ferries run to the islands from Larmor-Baden and Vannes, but they carry people, not bikes, so leave the machine on the quay and enjoy the crossing.