Aix-en-Provence or Biarritz?

Biarritz is the beach town of the two. The Grande Plage, the Côte des Basques and the long sands of Anglet are a short walk from the centre. Atlantic waves and currents keep swimmers between the flags, and the sheltered Port Vieux is the calm option.

From Aix the sea is always an outing, to the small pebbly coves of the Cote Bleue or the calanques near Cassis, and many visitors make do with the pool. The Mediterranean there is calmer when the mistral is not blowing, but you give up daily beach time for a drive.

Both cities eat well and in a strongly regional way, so the choice is between two cuisines. Aix is Provencal: morning markets on Place Richelme, long lunches of daube, tians and Coteaux d'Aix rosé, and calissons to finish.

Biarritz is Basque and centres on Les Halles, with fish from the Bay of Biscay, Bayonne ham, sheep's cheese, Espelette pepper and a habit of eating pintxos at the counter that Aix lacks. Neither offers much beyond its own regional and French cooking.

Aix has far more to see. The 17th- and 18th-century mansions of the Mazarin quarter, the fountains, the Cathedrale Saint-Sauveur with its Merovingian baptistery, Cezanne's studio and the Musee Granet fill a couple of unhurried days.

The heritage of Biarritz is the Second Empire resort itself: the imperial villa, the Art Deco casino, the Russian Orthodox church and the Rocher de la Vierge. Its museums are the aquarium and the ocean centre, so serious art means a trip out to Bayonne or across the border to Bilbao.

Neither town is made for big nights out, and both send keen clubbers elsewhere: Aix to Marseille, Biarritz to Bayonne or San Sebastián. The difference is in the rhythm. Aix's students keep the terraces around the Forum des Cardeurs busy during term, while Biarritz comes alive in summer with wine and pintxos around Les Halles and sundowners above the Côte des Basques, then goes quiet out of season.

Both are fine bases for the outdoors, but the landscapes are very different. Around Aix it is rock and heat: the ridge of Sainte-Victoire, the cliff paths of the Calanques, cycling in the Luberon and the Gorges du Verdon. Spring and autumn are best, because fire risk can close the massifs in midsummer.

Biarritz is about the ocean, with beginner surf breaks, paddleboarding and kayaking. On land there is the Basque Corniche path and the green Pyrenean foothills around La Rhune, kept green by the frequent rain.

Aix has the slightly richer choice of days out. Marseille is half an hour away and Avignon a short TGV ride, Arles, Nimes and the Pont du Gard make a run of Roman sites, and the Luberon villages from Gordes to Lourmarin are within an hour.

Biarritz's advantage is that its days out span two countries. San Sebastián and Hondarribia are across the border, Bayonne is next door and Saint-Jean-de-Luz is a train ride away, with Espelette, Ainhoa and Saint-Jean-Pied-de-Port inland. From either base, the villages are far easier with a car.

Biarritz is the easier choice with children. Surf lessons, the aquarium's seals and sharks, the ocean science centre for wet days and the calm Port Vieux cove give a family summer its shape, though the steep streets are hard work with a pushchair.

Aix is safe and largely free of cars in the centre, but its sights are mansions and museums. Hot afternoons push families to the pool, or out by car to the zoo at La Barben or the coast.

Aix is the simpler town on foot. The old town, the Mazarin quarter and the Cours Mirabeau make one compact, mostly pedestrian area, with small electric shuttles in the lanes. Its weak point is the TGV station, which sits out on the plateau.

Biarritz is walkable too, but hilly, with steps between the cliffs and the seafront. In its favour, the airport is on the edge of town and coastal trains run to the Spanish border. In both regions, the countryside means hiring a car.

Aix gives a shopper more to do. There are boutique lanes around Rue d'Italie and Rue Fabrot, high-street chains on the Allees Provencales, and on market days flower, textile and bric-a-brac stalls on the main squares. Calissons, santons, olive wood and Provencal prints are the things to bring home.

Biarritz offers a smaller browse among fashion boutiques and surf shops, with striped Basque linen, espadrilles and chocolate as the local buys. Neither has much luxury shopping or a major department store.

Neither is a budget choice, and there is little between them. Aix is dearest in July, when the opera festival fills its few central hotels, and a hire car for Provence adds to the bill. Lunch menus in the back streets and market picnics help.

Biarritz charges resort rates in July and August but gets noticeably cheaper out of season. Staying in Anglet or Bayonne, or eating pintxos at the market bars, brings costs down further.

Aix is by far the stronger of the two for the stage. In July the Festival d'Aix-en-Provence puts world-class opera in the courtyard of the Archbishop's Palace. Through the rest of the year the Grand Theatre de Provence, Ballet Preljocaj at the Pavillon Noir and the Theatre du Jeu de Paume keep a real programme going.

Biarritz's one great strength is dance, with its national choreographic company at the Gare du Midi and an autumn dance festival. Beyond that it has no opera house, and its programme is the touring shows of a small town.

Aix has a single thermal spa, the Thermes Sextius, on the site of the Roman baths that gave the town its name. Treatments there fill an afternoon, but they are not the reason to come. The real appeal is a slow pace that lasts all year except during the July festival.

Biarritz is the better choice for a vacation built around treatments. Instead of one spa it has several large thalassotherapy centres on the seafront, with heated seawater pools, hydrotherapy and cures lasting several days. Its calm season is the reverse of a beach trip, though: the beaches and streets are busy in July and August, so come in spring, autumn or winter to have the headland walks to yourself.