Biarritz or Segovia?

For a swimmer, Biarritz offers the real sea, though it is the Atlantic and not a calm bay. The water is only properly pleasant in late summer and stays fresh for the rest of the year. The surf and currents are often strong enough that you need to stay between the lifeguard flags. For a gentle swim, Port Vieux is a small cove where rocks keep the water calm. Outside July and August the sand is quiet and mostly left to surfers and walkers.

Segovia has no shore at all. A summer swim there means a hotel or municipal pool, or a cold dip in a reservoir or river pool in the Guadarrama foothills, so any beach days have to happen somewhere else on the trip.

Both have a strong regional cuisine, but Biarritz gives you more to explore. Les Halles is the centre of it, with Bay of Biscay fish, Bayonne ham, mountain sheep's cheese and pintxo counters busy from mid-morning, and there are seafood terraces and modern bistros beyond the market.

Segovia's cooking is built around a few great dishes: wood-roasted cochinillo and lechazo, judiones beans from La Granja and ponche for dessert. It makes a memorable lunch, but once you leave the asadores the choice is narrow and fine dining is thin.

Here Segovia is in a different league. The mortarless Roman aqueduct, the late Gothic cathedral, the Alcázar on the tip of the ridge, the old Jewish quarter and a run of Romanesque churches with arcaded porches fill a full day, and a second day at a slower pace is well spent.

In Biarritz the heritage is the resort itself: the imperial villa, the Art Deco casino, Belle Époque villas and the Rocher de la Vierge over the surf. It is pleasant to wander, but the museums are the aquarium and the ocean centre, so for older towns you need a day out to Bayonne or San Sebastián.

Neither is a late-night destination, but Biarritz has more going on in summer. People drink wine and eat pintxos around Les Halles, surfers meet for sundowners above the Côte des Basques, and a few clubs and the casino stay open into the small hours. Segovia's evenings are a tapas round near Plaza Mayor, with a few student bars at weekends and early nights in the cold months.

Each relies on a bigger neighbour for a proper night out: San Sebastián's bar streets for Biarritz, Madrid for Segovia.

The choice here is between surf and mountains. Biarritz is built around the ocean, with surf schools on the seafront, beach breaks at Anglet, and paddleboarding and kayaking when the swell drops. A cliff path heads south towards Spain, and inland are La Rhune and the green Pyrenean foothills, kept green by frequent rain.

Segovia looks onto the Sierra de Guadarrama. The Valsaín pine forests and the passes of Navacerrada and Cotos are within half an hour, and from there trails climb towards Peñalara at 2,428m and its glacial lakes. There is snow in winter, and the dry summers are good for walking, with griffon vultures over the Duratón gorge further out.

These are equally strong bases, and they point in different directions. From Biarritz the draw is the border: San Sebastián is under an hour away, Bayonne is next door, Saint-Jean-de-Luz is a short train ride, villages such as Espelette and Ainhoa lie inland, and Bilbao's Guggenheim makes a full day.

Segovia's trips take you into royal and medieval Spain. La Granja's palace and fountain gardens are twenty minutes away, Madrid is under half an hour by high-speed train, and you can reach Ávila, Pedraza and Sepúlveda too. In both places a car opens up much more.

Biarritz works better with children, especially in summer. The aquarium with its seals and sharks and the ocean science centre cover rainy days, children can learn to surf, and the calm Port Vieux cove suits the youngest.

Segovia has the Alcázar, a real turreted castle with a tower to climb, and the huge arches of the aqueduct, but no aquarium or theme park, so a day or two is enough. La Granja's gardens give children room to run. Both towns are steep work with a pushchair.

Both are compact and both are steep on foot. Segovia's sights line up along one ridge you can walk in a morning, but the high-speed station is a bus ride out of the centre. Biarritz spreads over headlands, with steps between the cliffs and the sea, but its airport is on the edge of town and coastal trains run to the Spanish border.

For the Basque villages or the Guadarrama trailheads, a car makes life much easier in either place.

Biarritz is the better place to browse, with fashion boutiques and surf shops between the Place Clemenceau and the market, striped Basque linen, handmade espadrilles and chocolatiers. Segovia has souvenirs along Calle Real, some ceramics and embroidery, and boxed ponche or La Granja beans to take home. For anything more you need Madrid, and neither town has department stores.

Biarritz charges resort prices, particularly in July and August, when rooms book up early and seafront restaurants are expensive. Market bars, pintxos at the counter, staying in Anglet or Bayonne, and visiting out of season all bring the cost down.

Segovia is clearly the cheaper stay. Family-run hotels and guesthouses are modestly priced and lunch menus in the newer town are fair value. Only the famous roasts by the aqueduct and summer weekends push the bill up, and midweek in winter it is inexpensive.

Biarritz has the edge thanks to dance. A national choreographic centre with its own ballet company performs at the Gare du Midi, a former railway station, and an autumn dance festival fills the town's stages.

Segovia's live arts come in festival bursts: the Titirimundi puppet festival in spring, and summer concerts in churches and palace gardens. Touring shows play at Teatro Juan Bravo. Neither has an opera house, though Madrid is close to Segovia.

Biarritz is one of the homes of French thalassotherapy. Its large seafront spas offer heated seawater pools and multi-day cures that people plan whole trips around, and outside summer the town settles into a slow pace of headland walks and long lunches.

Segovia has no bathing tradition and only a few hotel spas. Its calm comes from the old town once the coaches leave: evening walks along the walls and pine-scented air from the sierra.