Lagos, Portugal or Porto?

This is the clearest gap between the two. Lagos is a proper beach destination. Camilo, Dona Ana and the other coves lie beneath sculpted cliffs within walking distance of town, Meia Praia has room to spread out, and in summer the water is warm enough for long swims in calm, clear coves.

Porto does have sand, at Foz, Matosinhos and down the Gaia shore, and the metro gets you there. But the water stays cold, fog often rolls in in the morning, and the surf can be rough, so a beach day there is a break from sightseeing rather than the point of the trip.

Both cities cook fish over charcoal, but Porto is the better place to travel for food. It has its own dishes, the francesinha and tripas, plus bacalhau and roast pork in small family tascas, whole streets of grills in Matosinhos, the Bolhão market, and port tasted where it is aged in the Gaia lodges.

Lagos eats well if you choose carefully. Cataplana and the morning's catch are the reason to look, but the restaurants in the old town are mostly aimed at visitors, and the better meals are in plain places a street or two back.

Porto has much more to see. The whole historic centre is a heritage site, and it holds the Sé, the gilded interior of São Francisco, the Palácio da Bolsa and the azulejo hall at São Bento, with Serralves and Casa da Música adding modern architecture. It fills two or three full days.

Lagos has a single, sobering story to tell, about the voyages of discovery and the slave market of 1444. It is told through its walls, the harbour fort and the baroque interior of Santo António, and a morning's walk covers it.

Both are bar towns more than club towns, but Porto's nights are bigger and last all year. A large student population keeps the streets around Galeria de Paris full at weekends, and a few clubs by the river stay open till dawn.

Lagos is livelier than most places on the Algarve in summer, with backpackers, surfers and pub crawls in the old town lanes. From November to March it goes very quiet.

Lagos has the more dramatic landscape. You can kayak through the arches and grottoes at Ponta da Piedade, walk the cliff path to Luz and Burgau, and drive half an hour to the empty, surf-battered Costa Vicentina, with the Monchique hills inland.

Porto's nature is gentler and closer to the city. There is the Douro gorge under its bridges, a riverside cycle path out to the Atlantic, and the country's largest urban park. Gerês and the Douro vineyards are wonderful, but they are excursions rather than your doorstep.

Porto is the far better base for day trips, and most of them work by train. Guimarães, Braga, Aveiro and Coimbra are each about an hour away, and the scenic line up the Douro valley leads to the wine estates around Pinhão.

From Lagos the obvious outing is Sagres and Cape St Vincent, with Silves and Monchique inland. They are pleasant, but you need a car, and many visitors happily skip them for another beach.

For children, Lagos works better, mainly because of Meia Praia's gently shelving sand, boat trips to the grottoes and easy evenings by the marina. The steep stairs down to the coves and the water parks some way out of town are the drawbacks.

Porto has good outings: the aquarium, the cable car in Gaia, the Crystal Palace gardens. But its stepped streets are hard work with a buggy, and the cold sea means fewer easy beach days.

Porto is the one you can do entirely without a car. Its light-rail metro runs from the airport into the centre, out to the beaches at Matosinhos and across to Gaia, heritage trams follow the river to Foz, and trains reach the day-trip towns. The price is the walking, which is steep, on cobbles and stairs down to Ribeira.

Lagos is easy on foot within town, and a footbridge crosses the river to Meia Praia. Beyond town, the slow trains and infrequent buses mean most visitors end up hiring a car.

Neither city is a shopping destination. Porto has more to browse, with the high street on Santa Catarina, independent design and craft shops around Rua das Flores and Miguel Bombarda, and port to take home from the lodges.

Lagos keeps to ceramics, cork, sardine tins and surf gear in the old town, with honey and medronho brandy at the market.

Porto is the cheaper of the two. Tasca lunch menus, Douro wine and metro rides are easy on the wallet, and you save more by staying a little outside the old centre.

Lagos costs more in July and August, when beach rooms are in demand and the main-street restaurants charge resort prices. From October to May it becomes good value for long, quiet stays.

Porto wins this easily. Casa da Música is home to the symphony orchestra and also programmes jazz and electronic music, and the São João, Rivoli and Coliseu theatres stage drama and dance, though much of the theatre is in Portuguese.

Lagos has a modest cultural centre, fado evenings for visitors and cover bands in the bars. For anything serious you would go to Faro or Lisbon.

Neither has a bathing culture, and in both the spas are mostly in hotels. Lagos has a slight edge. It is easier to find yoga and surf retreats towards Luz and the west coast, and the Roman-era thermal springs at Caldas de Monchique are about an hour away.

In Porto, relaxing means a slow lunch, wine on a terrace above the Douro and the Serralves gardens. The thermal towns of the north take a full day out.