Seven days in Uruguay: the whole country fits along one coast road

The ferry from Buenos Aires puts you five hundred metres from the old town, so walk. You come in under the Portón de Campo, a reconstructed city gate with a wooden drawbridge and the remains of the eighteenth century wall running away on either side. This was a garrison town first and a port second.

Straight in is Calle de los Suspiros, the street of sighs, unpaved in the Portuguese manner with a stone gutter down the centre and a slope down to the water. It is the picture everyone has seen of Colonia and it takes two minutes to walk, which is why you should do it twice, once now and once after dark.

Then work out where the bastion is on the southwestern point and be sitting on the sea wall there before the light goes. The sun drops into the estuary in the direction of Buenos Aires, fifty kilometres away and below the horizon, and the whole town turns up to watch it. The last ferry has gone by then, which is the difference between staying and visiting.

Climb the lighthouse first, while the morning is clear. It was built in 1857, it is not tall, and from the platform you get the whole peninsula at once: the crooked Portuguese streets on one side, the Spanish grid on the other, and the estuary going out to nothing. The brick ruins of a Franciscan convent stand at its foot.

Casa Nacarello on the main square is the best of the town's small museums and takes twenty minutes: an eighteenth century Portuguese house furnished as somebody lived in it, with low doorways, thick lime-washed walls and warped glass in the windows. One combined ticket covers this and most of the others, and they close on rotating days, so buy it early and plan around what is open.

In the afternoon, the Basílica del Santísimo Sacramento on the Plaza de Armas is the oldest church in Uruguay. A chapel stood here in the 1690s and the present building went up under the Portuguese in 1808 after fire and gunpowder had dealt with its predecessors. The square outside has the footings of the governor's house dug out and labelled room by room.

That leaves the evening free, which in Colonia means the sea wall again.

The coach to Montevideo takes about three hours depending on how many towns it calls at, and it runs along the river the whole way. Take a morning departure and you have most of the afternoon.

Tres Cruces, where you arrive, is twenty minutes from the centre. Drop the bags and walk to Plaza Independencia, which is the hinge of the city: the old town on one side through an eighteenth century gate, the long commercial avenue on the other, and in the middle José Artigas on a bronze horse with his mausoleum underneath him, guarded around the clock.

A block into the old town is Teatro Solís, open since 1856 and still the country's stage. If there is nothing on, the guided tour takes you into the auditorium and backstage; if there is, buy a ticket, because it is cheap and the building is the point.

Go into the Ciudad Vieja under the Puerta de la Ciudadela, the last fragment of a city wall pulled down in the 1830s. Behind it Sarandí runs the length of the peninsula, pedestrianised, lined with nineteenth century facades in various states of restoration.

The Torres García museum is on that street. Joaquín Torres García worked in Barcelona, Paris and New York for decades before coming home, and in 1943 he drew South America with the south at the top and wrote that the north is our south. The drawing became the most reproduced image in Uruguayan art and a small argument about who decides which way up a continent belongs.

Eat at the Mercado del Puerto at the end of the peninsula, a nineteenth century iron hall now filled with grills burning wood. It is full of visitors and it is still where the beef is best, and it is a lunch place rather than a dinner one.

In the afternoon, the Museo Andes 1972. In October of that year a plane carrying a Uruguayan rugby team to Chile came down high in the mountains, and sixteen of the forty-five people aboard were alive when they were found seventy-two days later. The museum is small, built largely from objects the families lent, and told without any sensation at all.

Take a bus out to the great concrete bowl built in 1930 to hold the first World Cup and to mark a hundred years of the constitution. Uruguay won that tournament, beating Argentina in the final on this pitch in front of a crowd that had come across the river by boat, and won again in Brazil in 1950, and the country has never entirely got over either.

The football museum is inside, and the ticket normally gets you out onto the terraces and down to the pitch on days without a match. Shirts, boots, trophies and photographs, and an explanation of how a country of three and a half million people came to expect to win.

Then go down to the water and walk east. The Rambla runs twenty-two kilometres along the shore and the stretch from Parque Rodó through Punta Carretas to Pocitos is the best of it: fishermen, cyclists, dogs, and people sitting on the wall with a gourd and a thermos watching the widest river in the world go orange. Pocitos beach at the far end has the city's letters standing in the sand and a line of cafés behind it.

Two hours east by coach and the river turns into the Atlantic. Punta del Este is a peninsula of tower blocks between two beaches, one facing the calm water and one the open sea, and outside January it is largely empty.

Drop the bags and go straight back out west along the coast to Punta Ballena and Casapueblo. The painter Carlos Páez Vilaró began it in the 1950s as a summer shack and never stopped, adding rooms, terraces and staircases in white plaster over four decades without a drawing, until the whole cliff face had turned into a single sculpture with a hotel and a gallery inside it.

Go for the end of the day. There is a sunset ritual, a recorded farewell to the sun read by Páez Vilaró himself, that ought to be unbearable and is not, partly because the terraces face directly west over the water. Get there an hour before to see the galleries first.

Boats leave the harbour in the morning for Isla de Lobos, a low rock about ten kilometres offshore that holds one of the largest sea lion colonies in the southern hemisphere: tens of thousands of animals, along with fur seals and a lighthouse. You are not allowed to land, the boat circles, and the noise and the smell carry a long way before you see anything.

It takes two to three hours including the crossing, the sea is often rough on the ocean side, and trips are cancelled in bad weather, so this is the first thing to check the night before rather than the morning of.

Back on land, Punta del Este's own airport is fifteen minutes away with regional and seasonal flights, and Carrasco outside Montevideo is two hours west by road if you are flying long-haul.