Biarritz or Cascais?

Biarritz has the stronger beaches. The Grande Plage, the Côte des Basques under the cliffs and the long run of sand through Anglet give you kilometres of choice. The water is also a few degrees warmer in late summer. The catch is surf and strong currents, so most swimming happens between the flags or in the sheltered Port Vieux cove.

Cascais offers the opposite trade. Its small coves face south and lie right below the old town, so the water is calm, but the sand is limited and the sea stays cold. Guincho is the dramatic beach here, and it is better for watching the surf than for swimming.

Biarritz is the better place to eat. Basque cooking is a cuisine in its own right, and Les Halles is at the centre of it: Bayonne ham, sheep's cheese, Espelette pepper, piperade and axoa, with pintxo counters and Txakoli or Irouléguy wine around the market. There are also a few ambitious tables and a strong chocolate tradition.

Cascais eats mainly from the sea, with grilled sardines, clams in garlic and coriander, and seafood lunches looking over the waves towards Guincho. Beyond that the choice is narrow, and anyone who cares a lot about food tends to take the train to Lisbon for dinner.

Neither town is a big sightseeing destination, and both owe their look to royal summer visitors. Biarritz's heritage is in its buildings: the imperial villa of Napoleon III and Eugénie, the Art Deco casino, the Russian Orthodox church and the Rocher de la Vierge out on its footbridge.

Cascais has the more serious art. The Paula Rego museum in its red pyramid towers is a real gallery, while Biarritz's museums are mostly about the ocean, with its aquarium and ocean science centre. The Citadel and the cobbled old centre of Cascais take about a day.

Biarritz has a little more going on after dark, at least in summer. People drink and eat pintxos around Les Halles until late, surfers gather on terraces above the Côte des Basques at sunset, and a few clubs keep going into the small hours. Bayonne's old quarter is next door if you want more.

Cascais has a few streets of pubs, wine bars and cocktail terraces, plus the dressier casino at Estoril. Most of it is quiet by midnight, and a bigger night means Lisbon and keeping an eye on the last train back.

Both towns are good for a week outdoors, but in different ways. Biarritz is built around surfing, with beginner breaks and surf schools all along the seafront. Inland, the green Pyrenean foothills start within half an hour, and you can walk or take the rack railway up La Rhune.

At Cascais the wind matters as much as the waves. Kitesurfers and windsurfers come to Guincho, a cycle path runs past the dunes, and the cliffs end at Cabo da Roca. The misty, forested Serra de Sintra stands in for real mountains, and the summer nortada wind is good for sailing but tiring on a bike.

From Biarritz you can visit two countries, while Cascais has a capital city on its doorstep. On the Basque coast, San Sebastián's old town and bay are under an hour away, Bayonne is next door and Saint-Jean-de-Luz is a short train ride south. Inland are Espelette and Ainhoa, and Bilbao makes a long day, though many of these are easier with a car.

Cascais has the slight edge for variety. The coastal train runs past Belém into Lisbon, and the palaces of Sintra are just over the ridge. Further out, Mafra, Óbidos and even Évora give you plenty for a longer stay.

Biarritz is better for keeping children busy on rainy days, and Cascais has the calmer water. In Biarritz the aquarium has seals and sharks, the ocean science centre fills another afternoon, and older children can take surf lessons. The main beaches are rough, though, and the steep streets are hard work with a pushchair.

In Cascais the shallow coves are calm on most summer days, the flat promenade to Estoril is easy with a buggy, and the town park has peacocks and a playground. The aquarium and zoo are a train ride away in Lisbon, and the sea is cold for small swimmers.

Cascais is easier to get around. The seafront path to Estoril is flat, and the coastal train runs straight to Lisbon, so many visitors never need a car. You only need one for the wilder coast or the hill roads over Sintra.

Biarritz is compact but hilly, with steps and steep streets between the cliffs and the beaches. The airport on the edge of town is a plus, but reaching San Sebastián by train means changing at the border, and the Basque villages really need a car.

Biarritz is the better place to browse. Fashion boutiques and surf shops fill the streets between the Place Clemenceau and the market, and you can buy striped Basque linen, handmade espadrilles, chocolate and gâteau basque. Bayonne adds a few more streets of shops.

In Cascais, the souvenirs are more Portuguese: azulejo tiles, cork goods and tinned fish in decorative tins. It has less fashion, and serious shoppers head to Lisbon.

Neither town is cheap, but Cascais costs somewhat less. Rooms on the seafront are expensive there too, but simple cafés and set lunches in the back streets are cheap, and so is the train into Lisbon.

Biarritz charges fashionable-resort prices, especially for summer rentals and seafront restaurants. Eating pintxos at the counter or staying in Anglet or Bayonne helps, and both towns get noticeably cheaper outside July and August.

Biarritz has something Cascais does not: a resident ballet company from a national choreographic centre. It performs in the Gare du Midi, a former railway station turned theatre, and there is an autumn dance festival. Otherwise the programme is that of a small town.

Cascais has a long-established theatre company that performs in Portuguese, cabaret at the Estoril casino and a long-running summer jazz tradition. For opera, orchestras or fado, you need to go to Lisbon.

Biarritz is the place for a spa vacation. It has been a sea-bathing resort since the nineteenth century, and its large seawater spas offer heated pools, algae wraps and multi-day cure programmes that people book a whole trip around.

Cascais is restful in a gentler way, with early nights, coffee on the bay and hotel spas that continue Estoril's thermal tradition. It is better for an easy-going break than for a course of treatments, and summer weekends bring traffic from Lisbon.