But let's not get carried away here. Bus stations have to be able to take a good kicking on a Saturday night. Buses come charging brutally in and out of the stands, and have to have exactly the right amount and type of space to manoeuvre. You have to have somewhere for drivers and inspectors to lurk, out of sight of the hostile gaze of the queues. You have to have something to keep the rain off. A place to buy tickets and a cup of coffee is a positive advantage, as are lavatories. Bus stations therefore too often end up looking like overgrown filling stations, only usually less assured. All of the standard ingredients are present in Walsall, but done with unusual flair.

Peter Morris was the architect in charge of the project. He married Junge's filmic idea of heaven - as a great canopy pierced with holes, through which the gods can communicate with mortals - to the traffic circulation pattern of the site, just behind Walsall's high street. The result was a large oval shape. This went soaring into the air on slender steel "trees" as the bus station's canopy, duly pierced with large and small angled light shafts. It is 260 feet long by 150 wide. He then introduced a smaller glazed oval building beneath the canopy at one end for ticketing, cafe and so forth.

Contemporary artists Tanya Kovats and Alex Hartley worked with the architects on the design of the glazed walls and barriers (though another idea of theirs, for a light sculpture pulsing round the rim of the canopy, has not yet been funded). The bus station forms one end of a new landscaped square, with trees and seating, flanking the church of St. Paul. This is because the project was seen not just as a way to get people on and off buses, but more ambitiously as a way to regenerate the seedy backlands you always get behind the chain store service yards of your average high street.

As with film set design, a lot of the success of this building is to do with the art of illusion. The huge oval canopy appears to hover over your head. Unusually for something hanging so high in the air, it is made of smooth concrete. Brought to a fine chamfered edge, it appears to be immensely thick in the middle because of the depth of the holes punched through it. How do those slender steel pylons manage to support what must surely be an immense weight? But were you to get up onto the roof, you'd see that these deep angled holes project into the air: they're cowled tubes, and they look rather good. The canopy was cast on the spot on a network of steel mesh. It's very strong, but a great deal less massive than it seems. Similarly, you might think there's nothing to stop the whole building overturning like a picnic plate in a gale: but Morris's two-storey glazed building, rising to touch the underside of the canopy at one end, turns out to have a cruciform concrete core that stops the whole thing from rocking and rolling.

There were a few nerve-racking moments as the thing took shape (at one point it sagged a bit more than anyone expected). Making a huge concrete ellipse in mid-air, while dreaming of Paradise, isn't exactly easy. There are simpler ways to get a bus station built. But then other bus stations don't look like this one. What with buying the necessary bits of land, building the bus station, and making and landscaping the new square as well, the all-in cost came to around £6.5m. Remarkably good value for something that both transforms a large damaged bit of town, and makes taking the bus a pleasure. It might lack the film's famous "stairway to heaven", but with a bit of dry ice to help, you could quite imagine Raymond Massey, Marius Goring, and the other actorly deities, sitting around up there passing judgements on the passengers below.