Aix-en-Provence or Nantes?

Neither city is on the coast, and both make swimming a day out, but the seas are very different. From Aix you reach the Mediterranean: the pebbly or rocky coves of the Cote Bleue, Cassis and the calanques, with warmer water. These are small and crowded in August, and a car makes them much easier to reach.

From Nantes you reach the Atlantic: long, wide sandy bays such as La Baule and the coves around Pornic, about an hour away by train. The water is cooler and the season is shorter, but the sand and calm shallows suit small children better.

Both are good places to eat well, and the difference is regional. Aix eats the Provençal way: daily produce markets on Place Richelme, olives, goat's cheese, daube and rosé on long terrace lunches, with calissons for afterwards. Nantes cooks the lower Loire and Brittany: pike-perch in beurre blanc, which was invented here, coastal oysters, buckwheat galettes and Muscadet, with the covered Talensac market as its showcase. In Aix the setting is the treat. Nantes' bistros tend to give fairer value for what arrives on the plate.

Each needs two or three days, but they reward different interests. Aix is a town to look at. The Cours Mirabeau, the honey-stone mansions of the Mazarin quarter, fountains on every square and the Cezanne sites, from his studio at Les Lauves to the Bibemus quarries, make it a natural fit for art lovers.

Nantes tells a sharper historical story. The moated Château des Ducs de Bretagne houses a frank museum of the city's past, including its part in the slave trade, which the riverside Memorial to Abolition also marks. Add the leaning merchant façades of the Ile Feydeau, the Passage Pommeraye and the Jules Verne museum, and it is the better choice for history.

Students keep both towns livelier than their size suggests, but Nantes is where a night actually goes on. In Aix, evenings mean drinks on the terraces around Place des Cardeurs, and things wind down early. For a proper club night you go to Marseille.

Nantes starts in the packed pubs and wine bars of the Bouffay lanes. Later the crowd moves to the riverside bars and clubs in the old warehouses on the Ile de Nantes, which stay open into the early hours.

Aix has much more dramatic country on its doorstep. You can climb Sainte-Victoire to the Croix de Provence, walk the white cliffs of the Calanques, kayak the Gorges du Verdon or cycle through Luberon lavender. The catch is the summer heat and fire closures, which make spring and autumn the seasons for it.

Around Nantes the land is flat and full of water: canoeing or boat trips on the Erdre, the Loire à Vélo cycle route, and punting and birdwatching in the Brière marshes. It is pleasant and gentle, with the Côte Sauvage cliff paths as its wildest stretch, and there are no hills to climb.

Both make good bases, but Aix sits among a richer cluster of famous places. Marseille is half an hour away, Avignon's papal palace is a short TGV ride, and Arles, Nîmes and the Pont du Gard make a run of Roman sites. Then there are the Luberon villages of Gordes, Roussillon and Lourmarin, though for those you really need a car.

Nantes offers walled Guérande above its salt marshes, Angers and the Apocalypse Tapestry, Vannes on the Gulf of Morbihan, and Saumur and the Loire châteaux further out. Most of it is reachable easily by train.

Nantes is plainly the better city for children. The 12-metre mechanical elephant and the sea-creature carousel at the Machines de l'Ile are built for them, and the trams make getting about with a buggy easy. Within driving distance are the Port-Saint-Père safari park and Puy du Fou.

Aix is safe, and its pedestrian squares and fountains are pleasant for little ones. But its sights are mansions and museums, the summer afternoons are fierce, and families tend to retreat to a villa pool between drives out.

Both centres are compact and best explored on foot. The difference is what happens beyond them. Nantes has a simple tram and busway network, river shuttles across the Loire, flat streets for cycling and a central station with fast trains to Paris, so a car is only needed for the marshes and vineyards.

In Aix, the TGV station sits on the plateau outside town and needs a shuttle bus. The Provençal villages are poorly served by public transport, and parking in the centre is tight. Most visitors end up hiring a car.

Neither city is worth planning a trip around for shopping, and neither has luxury retail, but Aix makes a more appealing browse. Its boutique lanes around Rue d'Italie are tempting, and its market squares fill with fabrics, bric-a-brac and flowers. To take home there are santons, olive-wood ware and Provençal prints.

Nantes is more practical: chain fashion and a department store around Rue Crébillon, independent and second-hand shops near Decré, and the three-level Passage Pommeraye as its most striking setting. Berlingots and Guérande salt make good gifts.

Nantes is the cheaper stay. Hotels are plentiful at normal regional-city rates, and trams and a walkable centre keep transport costs down. Only the coast in high summer pushes costs up.

Aix has few hotels near the old town, and they are expensive, especially during the July opera festival. Much of what is on offer is boutique hotels and country houses. Terrace meals on the Cours Mirabeau are overpriced, and the hire car most visitors need adds to the bill.

The two are on a par, but their seasons point opposite ways. Aix's high point is July, when the Festival d'Aix stages opera in the courtyard of the Archbishop's Palace. Ballet Preljocaj at the Pavillon Noir gives it serious contemporary dance all year.

Nantes is busiest in winter with La Folle Journée, days packed with short classical concerts. It also has opera at the Théâtre Graslin, experimental work at the Lieu Unique and touring bands on the Ile de Nantes. Its giant street puppets give it a taste for outdoor spectacle that Aix does not share.

Aix is the more restorative place. The Romans founded it for its warm springs, and the water still runs through the town: you can see the mossy warm fountain on the Cours Mirabeau, and the Thermes Sextius spa stands on the site of the old baths. The town's slow lunches and quiet afternoons outside July do the rest.

Nantes has no bathing tradition of its own, so wellness there means hotel spas or an afternoon by the Erdre. The nearest real cure is seawater thalassotherapy at La Baule or Pornic, about an hour away.