Setúbal and Tróia, dolphins on the Sado and white sand on the other side.

Setúbal is a fishing city at the mouth of the Sado, with the Arrábida mountains on one side and, opposite, the sand spit of Tróia. A group of about thirty bottlenose dolphins lives in its estuary all year round, and setting out to find them by boat is the outing that brings almost everyone here. The other is to cross the river in a quarter of an hour to the white-sand beaches of Tróia, with some Roman ruins at the water's edge. From Lisbon it can be done in a day without a car.

How do you get there from Lisbon?

By car, about 50 km via the 25 de Abril bridge and the A2, or via the Vasco da Gama and the A12: about 45 minutes without traffic. Without a car, Carris Metropolitana has direct buses: line 4720 leaves from Oriente, with a metro connection from the airport, and the 4725 from Sete Rios; both end at the Várzea terminal, about 15 minutes' walk from the quay.

If you fly from Spain, you land in Lisbon: metro to Oriente and the 4720, or a hire car if you want to combine Setúbal with the Arrábida mountains.

How do you see the Sado dolphins?

By boat, from the quays in the centre of Setúbal. The Sado dolphins are one of the few resident colonies in a European estuary: they do not migrate, so there are trips all year round. Rotas do Sal, with a shop at the Mercado do Livramento, runs a two-hour trip round the bay for all ages from €45.57, which also takes in the Tróia sandbanks. Nobody can guarantee they will appear, and in a ground swell the trip may change or be cancelled: book for the morning, when there is usually less wind.

If you are staying on the other side of the mountains, boats also leave from Sesimbra; you will find them on the Serra da Arrábida page.

And Tróia?

Tróia is a sand peninsula about 20 km long between the estuary and the Atlantic. Atlantic Ferries crosses from Setúbal by passenger catamaran, in about 15 minutes and for €4.90 each way, or by car ferry, in about 25 minutes. On the river side the beaches have calm water and the Arrábida mountains opposite; on the ocean side, very long stretches of sand.

South of the quay are the Roman ruins of Tróia, the largest fish-salting centre of the Empire: factories with their tanks, houses, tombs and baths, occupied until the 6th century. They are open only from June to September; entry costs €6. Beside them, the Caldeira trail rings a tidal lagoon with herons and dunlins.

Where to eat and sleep?

In Setúbal you come to eat choco frito, the city's dish, served by the eating houses on Avenida Luísa Todi, next to the Mercado do Livramento, the Sado fish market. Go to the market in the morning.

To sleep by the beach, across the river: The Anchor Troia, with studios and apartments with a kitchen and an indoor pool, or the Tróia Design Hotel, a five-star in the same marina where the boats arrive, with a spa and casino.

When should you go?

From June to September for the Tróia beaches and the ruins. The dolphins are there all year: in spring and autumn the boats are less full and the sea is usually calm in the morning. In August, the car ferry has queues at weekends; the catamaran, fewer.