Nantes or Saint-Malo?

Saint-Malo has the beach at its door. The Sillon beach runs for 3km from the walls, small coves sit below the ramparts, and a tidal sea pool means you can still swim at low water. The Channel is cold, though, so time on the sand counts for more than time in the water.

From Nantes the beach is a day out. The sheltered bay at La Baule and the coves of Pornic are about an hour away by train, and the water there is a touch warmer. Still, you have to plan each beach day rather than stroll down after breakfast.

Nantes eats better. This is the home of beurre blanc, Muscadet comes from the vineyards just outside the city, and the Talensac market and the bistros from Bouffay to the Ile de Nantes give a broad and fairly priced choice.

Saint-Malo's strength is narrower. It means galettes with cider, salted-butter sweets and oysters eaten by the harbour wall at Cancale. Inside the walls many crêperies cater to day visitors, so the better meals are found out in Saint-Servan or along the bay.

Both grew rich from the sea, but Nantes has far more to show for it. The ducal castle holds a candid museum of the city's slave-trading past, and there is a fine art museum, a Gothic cathedral and the leaning merchant houses of the Ile Feydeau. That is two or three full days of sightseeing.

Saint-Malo's sight is the town itself. You walk the complete ramparts, look at granite houses rebuilt after 1944, and cross at low tide to Chateaubriand's grave on the Grand Bé. It is a memorable day, but there is little in the way of museums.

Nantes has a real night out, thanks to its students. Bouffay's lanes fill with bars and terraces, and later the crowd moves on to the clubs in the old dock warehouses of the Ile de Nantes.

Saint-Malo stops at a drink after dinner. A few pubs inside the walls stay busy on summer weekends, but the town goes quiet early the rest of the year, and the nearest clubs are in Rennes.

Saint-Malo's setting is the more dramatic. Tides of up to 13m reshape the bay twice a day, the GR34 runs along the cliffs to Pointe du Grouin and Cap Fréhel, and the water is busy with sailors, kayakers and kitesurfers, with seals off the islands.

Nantes's countryside is flat and quieter, made of river and marsh. You can follow the Erdre past manor houses, cycle the Loire à Vélo through vineyards or punt through the reed beds of the Brière. The rocky Côte Sauvage is an excursion rather than on the doorstep.

Both are excellent bases, and the difference is in the kind of trip. From Saint-Malo the headline is Mont-Saint-Michel, with half-timbered Dinan, Dinard across the estuary and summer ferries to Jersey close by, though most of these trips are easier by car.

Nantes points towards the Loire. Angers and its tapestry are under an hour by fast train, Saumur and the château country are within two hours, and Guérande's salt marshes and the walled town of Vannes give it a Breton side too. Much of this is reachable by rail.

Children are well served in both, in different ways. Nantes has the walking mechanical elephant at the Machines de l'Ile, the safari park half an hour away and Puy du Fou within a long morning's drive, and the trams make buggies easy.

Saint-Malo is a seaside vacation in itself, with sandcastles, the sea pool, pirate stories on the ramparts and the Grand Aquarium for wet days. Parents need to keep an eye on the fast tides and the cold water, and there is no theme park nearby.

Nantes is the easier place to get about. Its flat centre is walkable from the castle to the Ile de Nantes, the tram lines are simple to work out, river shuttles cross the Loire and cycling is easy.

In Saint-Malo the walled town and the seafront promenade are pleasant on foot, and buses and the Dinard boat cover the rest of town. Beyond it, buses are thin and summer parking near the walls is hard, so the car tends to decide your day.

Nantes offers a proper high street. The three-level Passage Pommeraye, Rue Crébillon's fashion and department store, and independent and second-hand shops around Decré give a fair choice.

Saint-Malo sells the Breton seaside: striped sailor tops, oilskins, faience, caramels and fine salted butter. It is good for gifts, but for clothes beyond that you would head to Rennes.

Nantes is the somewhat cheaper stay. Hotels in a large regional city are plentiful and moderately priced all year, and only the coast gets more expensive in high summer.

Saint-Malo charges resort prices in July and August, when rooms inside the walls and by the beach sell out early. Galettes and set lunches stay fair, and spring and autumn bring prices down considerably.

This is where Nantes pulls furthest ahead. There is opera at the Théâtre Graslin, a national orchestra, contemporary work at the Lieu Unique in the old biscuit factory, and La Folle Journée, which fills the city with short concerts each winter. The giant street puppetry adds spectacle outdoors.

Saint-Malo's stage life is concentrated into a few festivals: La Route du Rock for indie music, Étonnants Voyageurs for books and Quai des Bulles for comics. Outside those, the theatre's modest season and the odd cathedral concert are about all there is.

Saint-Malo is built for this. A large thalasso centre on the Sillon seafront offers heated seawater pools and treatments, and a quiet off-season break of low-tide walks and an afternoon in the pools is a long French tradition here.

Nantes is relaxed but has no seawater cure of its own. Rest there means a day spa, the Jardin des Plantes or an afternoon by the Erdre, and the thalasso centres of La Baule and Pornic are an hour's trip away.