However hard they try, though, nobody seems likely to top Bilbao's trick, where a single building, Gehry's Guggenheim, regenerated a whole city. (The museum has been extraordinarily successful as an art venue, with the attendance for some shows getting into the world's top ten.) But there is much more emerging than just the work of architectural superstars. Many of the new constructions have social purposes—city halls, schools, colleges (and in Leon, a striking mortuary!). I saw a lot of unsung felicities of design and imagination. Add to all this the infrastructure—highways, bridges, airports, railroad stations—and you get a terrific display of skills and style. Nothing seems too daring. If the spirit in Spain can be categorized at all, perhaps the best word for it would be Latin, a term used by Richard Rogers's partner, Ivan Harbour, who worked on both Barajas and Heathrow's new Terminal 5. "You could never build Barajas in London because it's Latin," Harbour said. "You could never build Terminal 5 in Spain. It wouldn't work. They're different animals."

But this idea of "Latin" is secular and singularly Iberian, and it should incorporate the hand of those who rode into Europe's southernmost peninsula from the desert, carrying with them the spore of cultures from as far off as China, Persia, and the Levant, and built cities far more sophisticated than anywhere else in Europe.

The airiness of Barajas—the rare lightness of a building this large—conveys something of the feel of a tent, or of many tents hitched together under that wavy roof, as though deflecting a searing wind. Was this, I wondered aloud to Rogers, another subconscious mutation of the architecture that began in the desert?

"One of the things that fascinates me," said Rogers, "is the whole Moorish invasion. That brought a very rich vein to the culture….In Spain, they have learned so much from North Africa."

It is their influence you feel in his airport, too. As in those Moorish courtyards, the air in the Barajas Terminal is, once chilled, free to circulate by convection through the high, open space of the canyons.

"So the Moors do still have an influence?" I suggested.

Rogers laughed. "We'll steal anything from anybody…if it works."