San Sebastian or Seville?

San Sebastian has the beach that Seville lacks. La Concha's sheltered bay of pale sand lies right in the centre, with quieter Ondarreta for families and Zurriola for surfers. The Atlantic season is short, though, and grey days come in summer too.

Seville is inland on the Guadalquivir. The nearest sand, at Matalascañas or Mazagón, takes a car or coach and most of a day. In the city itself, swimming means a rooftop or municipal pool, so people who want the sea usually add a few nights on the coast.

Both cities eat standing at the bar, but San Sebastian takes the habit further. In the Parte Vieja and Gros each pintxo bar has its own speciality, some made to order, and txakoli is poured from height. Above the bars are several of Spain's most celebrated restaurants, and the cider houses of Astigarraga open from January to spring.

Seville's tapas are plainer and more traditional: spinach with chickpeas, salmorejo, fried fish and jamón, with manzanilla or cold beer in tiled bars across Santa Cruz and Triana. It has little top-end dining, and neither city offers much cooking from outside its own region.

On culture, Seville is far ahead. The Real Alcázar, the cathedral with the Giralda and the Archivo de Indias form a UNESCO-listed trio. Add Plaza de España, Casa de Pilatos and the Murillos and Zurbaráns of the Museo de Bellas Artes, and three or four days fill easily.

San Sebastian is better seen as a handsome townscape than as a list of sights. There is the Parte Vieja, rebuilt after the fire of 1813, the late 19th-century streets around Buen Pastor, the castle on Monte Urgull, the San Telmo Museum and Chillida's Peine del Viento at the end of Ondarreta. Two or three days cover it.

Neither city is a place for serious clubbing, but Seville stays out much later. Dinner starts around ten, and the Alameda de Hércules, Triana and the squares around the Alfalfa stay busy into the early hours. In summer there are open-air bars along the river, and at the April Fair the whole city stays out all night in the casetas.

San Sebastian's evenings are excellent while the pintxo crawl lasts, but afterwards the choice shrinks to a few late bars in the old town and Gros. Outside summer and the Semana Grande, a weeknight there mostly means dinner and drinks.

San Sebastian has much more landscape that you can walk to from your door. Monte Igueldo and Monte Urgull frame the bay, and a cliff path runs from Monte Ulia to Pasaia. The walk over Jaizkibel to Hondarribia is among the finest coastal walking in northern Spain, and surfing and paddleboarding are right on the doorstep.

Seville is surrounded by flat farmland and olive groves. In the city, nature means María Luisa Park and the river. Further out are the Doñana wetlands, with flamingos and migrating birds, and gentle walking in the Sierra de Aracena. In Seville the summer heat rules out most outdoor activity, whereas San Sebastian's drawback is rain.

Both are excellent bases, but they point in different directions. San Sebastian's outings are short and cross a border: Bilbao and the Guggenheim, walled Hondarribia, Biarritz and Bayonne on the French Basque coast, Pamplona, and the Rioja Alavesa vineyards.

From Seville the day trips lead to monuments and Andalusian towns. Córdoba's Great Mosque is under an hour away by high-speed train, and Roman Itálica, Carmona, the sherry bodegas of Jerez and the old port of Cádiz are all easy days out. Granada is better done overnight.

San Sebastian is the easier city with children. It has calm, sheltered beaches in the centre and a flat, car-free promenade. There is also the aquarium with its walk-through tunnel, the Eureka science museum and the old funfair on Monte Igueldo, though rain can rule out the beach for days at a time.

Seville welcomes children in its squares just as warmly, and María Luisa Park, the Alcázar maze and the theme park on La Cartuja all help. However, summer heat regularly passes 40°C, which makes July and August hard work with small children.

Both centres are flat and walkable, but San Sebastian is smaller and simpler to get around. The Parte Vieja, La Concha, Gros and Zurriola are minutes apart along the river and the promenade, and bike lanes follow the waterfront. Euskotren trains run to the French border and towards Bilbao.

Seville's centre takes about half an hour to cross on foot, through narrow pedestrian lanes. A tram, one metro line, buses and a good public bike scheme back it up. The real obstacle is summer, when a walk at midday becomes an ordeal.

Seville has more for shoppers. Triana's pottery workshops sell hand-painted tiles, and the shops around Calle Sierpes and Calle Cuna sell flamenco dresses, shawls, fans and guitars, much of it made for locals getting ready for the Fair. Sierpes and Tetuán have the high-street chains, and the Thursday flea market on Calle Feria is good for browsing.

San Sebastian's shopping is smaller, and much of it is edible. There are espadrilles and berets in the Parte Vieja, surf shops in Gros, and txakoli, Idiazabal cheese and preserved fish from La Bretxa. Neither city has much in the way of luxury labels.

Seville costs far less. Tapas and drinks are cheap, you can walk almost everywhere, and rooms are moderately priced for most of the year. The steep exceptions are Holy Week and the April Fair.

San Sebastian is one of the most expensive places to stay in Spain. Hotel rooms are scarce and summer prices climb sharply, and the famous restaurants are a real splurge. A careful pintxo crawl, the free beaches and the walks keep costs down, but travelling outside the summer peak makes the biggest difference.

Seville has more to see on stage, above all because of flamenco. It is performed every night in the tablaos of Santa Cruz and Triana and in the peñas where local fans gather. The Teatro de la Maestranza stages opera, in the city where Carmen is set.

San Sebastian's music is concentrated in summer. Jazzaldia comes in July, with free concerts on Zurriola beach, and the Quincena Musical brings orchestral music and opera in August. The rest of the year the Kursaal and the Victoria Eugenia offer a quieter programme.

San Sebastian has a genuine seaside bathing tradition. It lives on in the thalassotherapy spa in the old bathing pavilion on La Concha, with seawater pools that look straight onto the bay, and the small, orderly city is a calm place to stay.

Seville's equivalent is a few Arab-style bath houses in old mansions, which make an atmospheric evening, along with its cool courtyards and the Alcázar gardens. Noisy streets at night and the crowds at Holy Week and the Fair make it a less restful place overall.