In the far south of Brazil, a stone's throw from the Uruguayan border, Rio Grande looks nothing like the usual images of the country. Here there are no granite mountains or rainforest: just a vast lagoon, plains as far as the eye can see and an old centre with Portuguese façades weathered by the South Atlantic winds. It's the oldest city in the state of Rio Grande do Sul, founded in 1737 to guard the entrance to the Lagoa dos Patos, and its cruise pier is only about two kilometres from the centre.

First steps in the old town

From the terminal, a few minutes' walk or a short taxi ride takes you to the old streets. The São Pedro Cathedral, in pastel tones, has watched over the city since the 18th century; around it stand former mansions, warehouses from the days when the city grew rich on maritime trade and shaded squares where residents meet in the late afternoon. The pace is peaceful, almost provincial, and there's never any need to hurry. Take the time to notice the details: azulejos inherited from Portugal, ornate cornices, signs from another century. Many buildings are still awaiting restoration, and this slightly sleepy-beauty air is part of the place's character.

The oceanographic museum, a big surprise

Rio Grande is home to one of the most important oceanographic museums in South America, affiliated with the local federal university. Whale skeletons, shell collections and tanks devoted to the region's wildlife tell the story of the meeting between lagoon and ocean. For a family port call, it's the safest bet of the day, a few minutes from the heart of town.

The Barra jetties and Cassino Beach

Excursions often head to the Molhes da Barra, two stone jetties several kilometres long that frame the channel linking the Lagoa dos Patos to the Atlantic. Anglers cast their lines there, cargo ships pass close to the rocks and the offshore wind sweeps over everything. Right next door begins Praia do Cassino, considered one of the longest beaches in the world: a strip of sand running toward Uruguay for more than 200 kilometres. You don't come here for palm trees, but for a grey-green immensity that is impressive in its own way.

Gaucho country

The hinterland belongs to gaucho culture, that of the horsemen of the plains. It's to be tasted more than visited: slow-grilled churrasco, mate tea shared from the gourd, traditional music on feast days. In the streets, you'll notice residents carrying their thermos under their arm at all hours of the day — a ritual visitors are happy to be initiated into. Some tours continue to Pelotas, a neighbouring city known for its sweets inherited from the 19th century, when trading fortunes vied with one another in elegance.

Pointers for the port call

Before casting off

Rio Grande is one of those port calls that promise nothing and end up giving a great deal: a special light over the lagoon, unpretentious streets, a mate offered with a smile. You return on board having seen a Brazil few travellers know, and that may well be its greatest asset.