Salamanca or San Sebastian?

There is no real contest. Salamanca lies far inland on the Castilian plain. A summer swim there means a municipal pool or a river beach on the Tormes, fine for an afternoon and no more.

San Sebastian has one of the great city beaches in La Concha, a sheltered bay of pale sand a few minutes from the old town. Quieter Ondarreta sits beside it, and Zurriola faces the open sea for surfers. The catch is the Atlantic: the season is really only July and August, and grey days interrupt it.

Salamanca eats heartily but simply. Its table is built on pork and the plain, with Guijuelo ibérico ham, hornazo and roast suckling pig served in generous portions at student-filled counters around the Plaza Mayor, and fish barely features.

San Sebastian is in another league, and many visitors plan their whole trip around its meals. Where Salamanca slices ham, the bars of the Parte Vieja cook small dishes to order from what the Bay of Biscay brings in, such as anchovies and squid. Above the counters there are more top-flight restaurants than you would expect in a city this size. Both kitchens stay firmly regional, so neither is the place for food from elsewhere.

Salamanca is the better place for sightseeing. The whole old city is a World Heritage Site built of golden sandstone. Within a few streets stand the baroque Plaza Mayor, the Plateresque University façade, the Old and New Cathedrals, the Clerecía and San Esteban, all floodlit after dark. The museums are modest, with Casa Lis the exception.

San Sebastian offers an attractive townscape more than a set of monuments: elegant 19th-century streets, the Parte Vieja rebuilt after 1813, the Miramar Palace and the castle on Monte Urgull. The San Telmo Museum and Chillida's Peine del Viento are its highlights. Two or three days cover either city.

Salamanca has the bigger night out. Tens of thousands of students fill the bars around the Plaza Mayor, Calle Bordadores and Gran Vía from Thursday to Saturday, and the night ends in dance bars and small clubs well past 3am. It is aimed at a young crowd and goes quiet in high summer.

In San Sebastian the evening is a pintxo crawl, sociable and noisy in the Parte Vieja, but there are few places to go once the bars close. The city stays out later in summer and during Semana Grande, which is exactly when Salamanca's students have gone home.

San Sebastian has the landscape on its doorstep. Green hills ring the bay, and Monte Igueldo and Monte Urgull give the classic views. The cliff path from Monte Ulia to Pasaia, and on over Jaizkibel to Hondarribia, is superb coastal walking, with surfing and paddleboarding in the water below.

Around Salamanca the land is the flat, wheat-coloured Meseta, with paths along the Tormes for a stroll. The more rewarding country starts about an hour out and needs a car: the chestnut forests of the Sierra de Francia, the higher Sierra de Béjar and the granite canyon of the Arribes del Duero.

Both make good bases, for different kinds of outing. Salamanca is the base for walled and Romanesque Castile. Ávila and Zamora are about an hour away, Ciudad Rodrigo lies towards Portugal, and the villages of La Alberca and Mogarraz are well preserved but awkward to reach without a car.

San Sebastian offers a wider choice that is easier to reach. Bilbao and the Guggenheim, Hondarribia, Pamplona and the French Basque coast at Biarritz and Saint-Jean-de-Luz are all an hour or so away, much of it by bus or train. The Rioja Alavesa vineyards are under two hours away, so a second country and a wine region both fit easily into a week.

San Sebastian is the easier choice with children. Calm beaches in the centre, a flat car-free promenade, the aquarium's walk-through tunnel, the hands-on Eureka museum and the funicular up to a small funfair keep them busy for several days. Rain is the main thing that can spoil it.

Salamanca is safe and largely pedestrian, and children enjoy finding the frog and the astronaut carved in the stone. There is no zoo, aquarium or beach, though, and summer afternoons are fiercely hot. It works best as a stop on a longer family trip.

You can see either city on foot. Salamanca's sights sit in a compact, mostly pedestrian old town about 20 minutes across. Its cobbles and slopes need care with a pushchair, and getting into the sierras really means hiring a car.

San Sebastian is flatter and has bike lanes along the waterfront. The Euskotren runs to the French border and towards Bilbao, so you can see more of the region without driving.

Neither is a shopping destination, and in both the best things to take home are edible. Salamanca has high-street chains on Calle Toro and Calle Zamora, ibérico ham and cheese from the Mercado Central, and charro silver filigree jewellery as its one distinctive craft.

San Sebastian has a little more to browse: independent boutiques in the Centro, surf and design shops in Gros, and espadrilles, berets and tinned anchovies in the Parte Vieja.

Salamanca costs far less. Students keep bar prices low, a drink often comes with a free tapa, and old-town rooms are moderately priced. Entry to the cathedrals and the university is the main extra cost.

San Sebastian is one of the most expensive places to stay in Spain, especially in summer, and its famous restaurants are a serious splurge. The beaches, walks and buses cost little, and coming outside the summer peak saves the most.

San Sebastian has more to offer, mostly in summer. Jazzaldia takes over July, and the Quincena Musical brings orchestral music and opera in August. Outside the festivals, the Kursaal hosts the Basque National Orchestra and the ornate Teatro Victoria Eugenia stages plays and concerts.

Salamanca relies on the Teatro Liceo, touring productions and the university's choral concerts. Its best-loved music comes from the caped tunas singing under the Plaza Mayor arcades, which is charming street music, not a concert season.

San Sebastian has the only real bathing institution of the two: the historic pavilion on La Concha, which carries on the old sea-bathing tradition as a thalassotherapy spa looking onto the bay. Promenade strolls add to the calm.

In Salamanca itself there are only hotel spas and small Arab-style baths, with the mineral springs of Ledesma and Baños de Montemayor a drive away. Its restfulness comes from quiet cloisters, siestas and long lunches.