Just finished, out in the north-west near the airport, is the new Congress Centre, designed by Sir Norman Foster to be an instantly recognisable landmark on the edge of town, an asymmetrical oval form rising to a tall colonnaded entrance canopy. It is as delicate and light as these places are usually squat and windowless. Sna Barbera inherited plans for a conference centre here - and made the crucial decision that it should be by an internationally-acclaimed architect. She appointed Foster directly, and has kept a close eye on him since. I was told she has a habit of turning up to site meetings unannounced - but even so I was surprised to find her there at a quarter past midnight, just hours before she officially opened the huge, triple-auditorium building. She was urging on the workmen who were desperately planting flowers and laying turf around the building in a last-minute dash to meet the opening deadline. Senora Barbera made sure they worked all night.

Valencia Congress Centre by Foster and Partners.

Foster himself pays tribute to his client. Hands-on? He'll say. "This building," he remarks, "started with the cultural imperatives of the mayor and her ambitions for the city." The mayor in question was not above telling the world-famous designer what to do. It's clad in stone as well as Foster's trademark glass because that is what she wanted. And far more of the materials and craftsmen involved are local than is usual with a building of this type. Even so, it is relatively cheap at the equivalent of £25 million. "It wouldn't be unusual, even in Spain, to spend three times that amount on a building of this kind," says Foster as he dodges the ubiquitous camera crews. Ever since he married a popular Spanish media academic a couple of years back, Foster has been adored in Spain. Now that his bride has just produced a baby, the TV teams are ecstatic. The mayor of Valencia made a wiser choice of architect than even she knew.

arts centre by Santiago Calatrava & "Hemispheric" IMAX cinema etc by Calatrava

However, the Congress Centre, designed to bring thousands of business delegates to the city, is small-scale compared with what is happening the other side of the city. There, a hugely ambitious cultural complex is being built, at the end of the unique broad linear park made in the 1960s from the bed of the diverted (because previously flood-prone) River Turia. There is to be a science museum, arts centre with (naturally) an opera house, and, already built between these two, the planetarium/mega-cinema known as the "Hemispheric", its eye-like appearance being one of its architect's trademarks. The entire complex, costing £150 million, is designed by the Spanish architect Santiago Calatrava, who is almost as internationally famous as Foster - and who happens to have been born in Valencia. Calatrava has also given the city one of his characteristic tilting-arch bridges, plus the central Alameda station on the new metro system.