Carolyn Boyd finds unexpected quiet when she visits the Cotentin Peninsula’s secret beaches at the height of summer

It’s a Saturday in August, and everything I know about beaches on Saturdays in August has been proved wrong. There’s not a cloud in the vast cyan sky, the silky sand feels sublime between our toes and — here’s the thing — there is not a single person to be seen. My family and I have the expanse of golden sand on the Plage de Montmartin-sur-Mer to ourselves. We can’t see the sea either, mind you, because the tides in Mont Saint-Michel bay are so strong that the sea retracts by a good mile at low tide. But no matter. This is our beach today and we’re going to jump, run, play and build sandcastles to our hearts’ content.

Like all the beaches we visit over a week on the west coast of the Cotentin Peninsula in Normandy, Montmartin feels like a well-kept secret. To the west are the tourist hordes descending on Mont Saint-Michel; to the east they are paying their respects and learning about the D-Day landings. The deserted beach means we have had to be organised, though — there is no ice-cream kiosk or café, so we have brought a picnic prepared by our B&B, Le Castel. The genial and family-friendly guesthouse, 15 minutes away, has expansive gardens, a huge play tent, swimming pool and four large and luxurious family suites decked out in period furniture.

The next day we tear the kids away from the fun at Le Castel to explore the coast north of Montmartin. At Gouville-sur-Mer we park on the seafront, where oyster farmers’ tractors trundle up a slipway, pulling the morning’s catch, and the lifeboat station’s flagpole clinks in the breeze. To the south, rows of colourful-roofed beach huts are tucked among the grassy dunes and the children hare off to explore, following the sandy paths that weave between them.

We follow on, nodding to the few people using the huts — a large family tucks into a picnic brunch, while at another a group of teenagers play pétanque on the uneven sand. For the most part, however, the huts are closed, no doubt awaiting weekending locals, while we stroll on the empty paths between them before picnicking on the beach. There are no ice-cream kiosks at Gouville either — for that we must go south to Granville.

I expect this yachting hub, the birthplace of Christian Dior, to be achingly chic, but we find a charming seaside town. It’s a little scruffy here and there, but there’s plenty of ice cream and a buzzing morning market. The Haute Ville is its enchanting historic quarter, where clifftop ramparts enclose a warren of steep cobbled streets lined with pale-stone, white-shuttered mansions.

We follow a narrow alley towards the ramparts and walk along the walls, gazing out to sea and at the beaches below. A set of narrow steps leads down to a beach under the cliffs, and the low tide makes it ideal for an afternoon of seashell collecting and rock-pooling. For me, though, there’s the lure of couture, so I leave husband and kids at the beach to visit the Musée Christian Dior.

The museum is set in the designer’s much-loved childhood home, the pink Villa Les Rhumbs, which is surrounded by manicured rose gardens. Inside, I wander between exhibits that tell the story of his life — cut short by a heart attack at 52 — and mannequins in glass cases that showcase a chronology of his designs. The detail is incredible and I spend a long time admiring the intricate embroidery, lavish ruffles and pleats. They include, of course, his famous New Look of exquisite hourglass dresses that exemplify his “perfect” female measurements of 34-21-35 — achievable only after many days without ice cream.

The path back to the Haute Ville takes me along the town’s promenade, past a row of newish beach huts, by which couples and families sit out on deckchairs, picnicking and chatting in a more typical beach scene for August. A day in “town”, however, makes us crave the empty beaches we found earlier in our trip, so the next day we continue north in search of more Robinson Crusoe solitude. The road up through the Cotentin Peninsula weaves past meadows divided by winding creeks, and hamlets of shuttered stone cottages. We arrive at Barneville-Carteret, a small but lively resort that promises a coastal walk and more beaches. After building a quick sandcastle on Plage Potinière, the glorious golden beach overlooked by a neat row of blue and white huts, we walk around the Chemin des Douaniers headland on a precipitous path that looks down on blackened rocks lapped by sea.

The lighthouse high on the hill above us looks out towards Jersey; we tramp around the grassy headland to meet the most breathtaking view — miles of fine white sand stretch as far as we can see, with just a handful of bathers, their tiny figures and colourful towels barely visible. Plage de la Vieille Église is a jaw-dropping sight. We teeter down the path that looks out over the protected dunes and on past the ruined church from which it takes its name. The legend goes that it was built and dedicated to an Irish saint who vanquished a giant child-eating dragon that lived in the cave on the beach. It’s not something I expect to discover about a beach, but then again, I thought I knew about beaches in August.

Need to know
Carolyn Boyd and her family stayed at Le Castel, a family-friendly chambre d’hôtes 15 minutes from Montmartin-sur-Mer at Montpinchon. Family suites with two en suite bedrooms cost from £1,500 half-board for a family of four for seven nights in August (00 33 233 17 00 45, le-castel-normandy.com). They travelled to France with Brittany Ferries, which has crossings from Portsmouth to Saint-Malo for £579 return for a family of four and a car, including an en suite cabin on the outward overnight sailing (0330 1597000, brittany-ferries.co.uk). For more information, see en.normandie-tourisme.fr