Cascais or Marbella?

What separates the two is the water. In Cascais the beaches are close at hand: the coves of Conceição, Duquesa and Rainha lie just below the old town, the promenade leads on to Estoril, and surfers take the train a few stops to Carcavelos. But the Atlantic stays bracing even in August, so a swim is a quick, cold plunge. At windswept Guincho the currents keep most people on the sand.

Marbella is better for long days by the sea. The water is a few degrees warmer and stays pleasant for swimming well into autumn, and the shore runs for kilometres, from La Venus and El Fuerte in town past Puerto Banús to the quieter dunes at Cabopino. The sand is grey rather than white, but there is always a sunbed or a beach grill with sardines on skewers nearby.

Marbella offers the wider range. You can have tapas and fried fish in the old town, ajoblanco in summer and genuine fine dining along the Golden Mile. Its weak spot is the middle ground around the port, so it pays to walk a few streets inland.

Cascais is narrower and more devoted to the sea. You get grilled bream, clams and the harbour's daily catch, the Mercado da Vila in the morning and long seafood lunches on the road to Guincho. Anyone who wants ambitious cooking takes the train to Lisbon.

Neither town is a heavyweight for sights, and both fill an easy day, but they differ in kind. Cascais has the elegance of a former royal summer retreat, with aristocratic villas, the Citadel and the Paula Rego museum in its red towers. Marbella's heritage is older and Andalusian: whitewashed lanes around the Plaza de los Naranjos, Moorish wall fragments, a Roman villa with mosaics and Dalí bronzes along the Avenida del Mar.

Marbella is the place for a real night out in summer. It keeps Spanish hours, with beach clubs whose DJs carry on into the evening and polished, moneyed clubs at Puerto Banús that stay open until dawn. The scene shrinks sharply from November.

Cascais is far quieter. It has pubs, wine bars and cocktail terraces in a few old-town streets, plus the casino at Estoril for a dressier evening. For anything later you need Lisbon and a plan for the last train home.

Cascais has the edge for wild scenery close at hand. You can cycle from town past Boca do Inferno to the dunes and wind-blown surf of Guincho, walk the cliffs at Cabo da Roca and follow misty trails through the Serra de Sintra. Kitesurfers and windsurfers come for the steady summer wind.

Marbella's outdoors is more about mountains. You can climb La Concha above town and drive to the fir forests of the Sierra de las Nieves or the Caminito del Rey. Its mild winters make it a good walking base in the cooler months, though the coast itself is heavily built up.

Cascais is the stronger base, mainly because Lisbon and Belém are a train ride along the shore and Sintra's palaces are just over the ridge. Mafra, Ericeira and Óbidos fill further days, and you can reach Évora on a long one.

Marbella's list is also tempting, with Ronda's gorge, Málaga's Alcazaba and Picasso Museum, Gibraltar and white villages like Casares. Without a train, though, nearly all of it means hiring a car.

Marbella gives families more to fill the days. It has lifeguarded town beaches, warmer water, resorts built around pools and a culture that welcomes children at dinner. Animal parks, water parks and an aquarium lie along the coast, though you need a car to reach them.

Cascais is calmer and smaller, with shallow coves, a flat promenade and the peacocks of the Marechal Carmona park. The cold sea and the lack of attractions in town make it better for toddlers than for older children who want to be kept busy.

Cascais is much easier without a car. The harbour, coves, old centre and promenade are all within walking distance, and the coastal train takes you straight into Lisbon. A car only becomes useful for the hills and the far coast.

Marbella stretches from San Pedro to Cabopino along a motorway. Only the old town and central seafront work on foot, there is no train, and most visitors end up hiring a car or relying on taxis.

Marbella is the place for shoppers who want big labels. Puerto Banús lines international fashion and jewellery boutiques up opposite the yachts, with a department store beside the port. Away from the luxury brands there is little to browse.

Cascais offers a pleasant wander instead, with surf brands, azulejo tiles, cork goods and tinned fish in decorative tins. For serious fashion you go to Lisbon.

Both are upmarket resorts that are dear for their countries, but Cascais is somewhat easier on the wallet. Its back-street set lunches and cheap train into Lisbon help keep costs down. In Marbella, beach clubs, prime sunbeds and dinners around Puerto Banús add up quickly, and summer room rates climb steeply. In both towns, going outside July and August makes the biggest difference.

Neither town is a destination for the stage, and both send serious audiences to the nearest city: Lisbon for fado and opera, Málaga for classical music and real flamenco. The difference is in the summer offer. Cascais has its long jazz tradition and the Teatro Experimental's plays in Estoril. Marbella has big pop and rock acts in its quarry amphitheatre and flamenco shows aimed at visitors.

Both towns are best for an unhurried stay out of season, but they reach it differently. Cascais relies on its quiet pace and Estoril's old spa and thalassotherapy tradition. Marbella has more dedicated retreats, detox clinics and Arab-style bathhouses in the hills and along the Golden Mile, along with mild, sunny winters for golf and long lunches.