Bilbao, and the museum that changed a city

There is a phrase in town planning, the Bilbao effect, that means the hope that a single remarkable building can turn a city's fortunes round. It is named after a museum on a bend of the Nervión, and the city that built it is worth understanding before the building is, because the museum makes much more sense once you know what was there before.

Bilbao was founded in 1300 as a port on the river, some way inland from the Bay of Biscay. Its old quarter, the Casco Viejo, began as seven streets, the Siete Calles, packed tight on the right bank, and its business was trade: Basque iron and wool going out, everything else coming in. From the 1870s the hills around it gave up iron ore by the shipload, and Bilbao became a city of blast furnaces, steelworks and shipyards along both banks of the estuary. It grew rich, smoky and serious. By the late twentieth century much of that industry had gone into decline, and the riverbank in the middle of the city was a stretch of old docks and rail yards.

Then, in 1983, the Nervión flooded. Water filled the streets of the Casco Viejo to a depth of about three metres in places, and 34 people died. The rebuilding that followed was the start of a much longer argument about what Bilbao should become.

The building

The answer, or the most famous part of it, came from the Basque government, which approached the Solomon R. Guggenheim Foundation of New York in 1991 about opening a museum in the run-down port area. The foundation chose the Californian architect Frank Gehry. What he designed was not a box for pictures but something closer to a ship run aground, or a great silvery flower: curved forms of limestone, glass and titanium stacked against the river, so complicated that they could only be built with the help of digital modelling.

The titanium is the thing people remember. It is laid in thin overlapping sheets, like scales, and it changes with the weather. Under the grey skies that the Basque coast is known for, the building is pewter; when the sun comes out, it warms to something nearer gold. Gehry is said to have chosen it after watching a scrap of the metal change colour in the rain, which is the kind of story architects tell, and it has the advantage of being a good one.

The Guggenheim Museum Bilbao opened in 1997. Within a few years the phrase had been coined, and economists were writing papers about the visitors, hotel nights and new businesses that followed it. Whether one building can really do all that, or whether it simply became the symbol of a regeneration that was happening anyway, is a fair question. Bilbao itself would say the answer is both.

Around the museum

You do not need to go inside to see much of it. Outside the main entrance sits Jeff Koons's Puppy, a terrier the height of a house, planted all over in living flowers. On the river side, Louise Bourgeois's Maman, a huge bronze spider, stands on long thin legs, and people walk underneath her to take photographs looking up. Both have become as much a part of the city as the building behind them.

Inside, the galleries are of every shape, and the exhibitions change; the building is the constant.

The museum was only the most visible piece. Bilbao also built a metro, opened in 1995, with stations by Norman Foster, whose curving glass entrances rise out of the pavements like the shells of giant woodlice; the people of Bilbao call them fosteritos. The old docks of Abandoibarra became a riverside of parks, walks and new buildings, and the waterfront between the museum and the old town is now a walk worth taking for its own sake.

The old town, and what to eat in it

For all the titanium, it is the Casco Viejo that most visitors end up loving. The Siete Calles are still there, narrow and tall, with glassed-in balconies and bars along every one of them. The Basque habit is the pintxo, a small something on bread or on a cocktail stick, laid out along the counter and eaten standing up with a small glass of wine or cider, before moving on to the next bar. On the edge of the old town, beside the river, the Mercado de la Ribera has been the city's market since its present building opened in 1929; it was remodelled after the flood of 1983.

The old town and the museum are only a short walk apart along the river, and the contrast is the point: medieval streets at one end, a twentieth-century landmark at the other, and the river that made both of them in between.

Trips that start here

Bilbao's airport makes it a natural starting point for trips into northern Spain, and the three holidays here all list Bilbao among their places. None of them is built around the museum; Bilbao is where they begin to head out into the country.

Travelsphere's seven-night Flavours of Spain's Basque Country & La Rioja takes in Bilbao, San Sebastián, Getaria and Hondarribia, crosses into France for Saint-Jean-de-Luz, Biarritz and Espelette, and comes back by way of Pamplona and the wine towns of Laguardia, Logroño and Haro.

Explore Worldwide's seven-night Trekking in Spain - Picos de Europa heads west into the mountains, with Sotres, the Garganta del Cares, Naranjo de Bulnes, Tresviso and Potes among its places. It runs from April to October.

Just You's seven-night Walking the Camino De Santiago lists Bilbao alongside Puente la Reina, Burgos, Astorga, O Cebreiro, Santiago de Compostela and Fisterra.

If you have an afternoon in the city before any of them, I would spend it the obvious way: the museum, the walk along the river, and an evening of pintxos in the Siete Calles.