Cascais and Estoril, the Lisbon coast at the end of the train line.

Cascais is the fishing village that the Portuguese court turned into a summer resort at the end of the 19th century, and today it is the easiest escape to the sea from Lisbon: the train leaves from the centre, runs beside the Tagus and then the ocean, and drops you five minutes from the bay. In a day you see the Cidadela and the marina, stroll to Estoril, walk to Boca do Inferno and, if you have time left, carry on to Guincho, a wild beach with the Sintra mountains behind.

How do you get there from Lisbon?

By train. The Cascais line leaves from Cais do Sodré, in central Lisbon, and reaches Cascais in about 40 minutes, with stops at Belém, Oeiras, Carcavelos and Estoril. Sit on the left on the way out: you see the river and then the sea. CP sells a 24- or 72-hour ticket valid on the Cascais, Sintra and Sado lines, and another that combines the train with several Cascais museums.

By car it is about 30 km on the A5, which has tolls, or on the Marginal, the coast road, slower and prettier. In central Cascais parking is expensive and in summer almost impossible: if you go by car, think about leaving it in a car park at the entrance and continuing on foot. The car makes sense for continuing along the N247 to Guincho and Cabo da Roca, or going up to Sintra through the mountains.

If you come from Spain by air, you land in Lisbon: metro to Cais do Sodré, with one change, and then the train. From the airport, by car, it is about 35 km.

What to see in a day?

Start at the bay, with the boats on Ribeira beach, and climb up to the Cidadela, the fortress that defended the entrance to the Tagus: its courtyards are open and there are artists' workshops. Continue through the park to the Casa das Histórias Paula Rego, the painter's museum with two red towers, and the Santa Marta lighthouse. From there, another 15 minutes takes you to Boca do Inferno, a sunken cave where the sea breaks.

After lunch, change direction: the seafront promenade runs from Cascais to Estoril in three flat kilometres beside the beaches. You return by train from Estoril or Monte Estoril.

If you have another day, or set out early, take a bike and follow the coastal path to Guincho beach: 9 km with the ocean on one side. There are surf schools there with lessons from age 5. From Guincho, the road climbs to Cabo da Roca, the westernmost point of continental Europe, which you will find on the Sintra page.

Where to eat and sleep?

For fish with the sea in front of you, Mar do Inferno, at Boca do Inferno, or Furnas do Guincho, a seafood restaurant on the rocks on the way to the beach. For an ice cream, Santini, which opened in 1949 and still makes its sorbets with fresh fruit.

To sleep, the Hotel Baía is on the bay and five minutes from the train; the Pestana Cidadela occupies part of the fortress, with a pool and spa, and admits small dogs; the Orbitur Guincho campsite is behind the dunes and open all year.

When should you go?

From April to October. In June and September the water in the bay is already warm enough to swim and there are fewer people than in August, when the train is full at weekends. Winter is mild and quiet, with a ground swell, which is when Boca do Inferno impresses. The north wind blows hard at Guincho almost every summer afternoon: it is good for kitesurfing and bad for your towel.