Now rising fast from its wasteland site in Greenwich, the Dome is on the scale of a World Expo – and like the very first of all Expos, the Great Exhibition of 1851 in London’s Hyde Park, it is all under one roof. Instead of the Great Exhibition’s famed Crystal Palace by Joseph Paxton, we have Richard Rogers’s Cyclopean crown of yellow masts. From these a web of cables is being spun which will support the immense curved Teflon-coated fabric roof that gives the Dome its name. At 320 metres across and 50 metres high, covering eight hectares, it’s typical Rogers bravura. The architectural radical who gave Paris the Pompidou Centre in 1976 has lost none of his theatrical ability, for all that he is now Lord Rogers of Riverside and rubs shoulders with the great and the good. And at £50m or so to build, the Dome is a snip – it’s the rest of the Experience, whatever that turns out to be, that is costing Britain’s National Lottery a total of £758m and is supposed to pull in 12 million visitors during the year 2000.

Alongside the dome, and being built even faster, is what seems to be a giant Stealth bomber. This other great roof turns out to be by Rogers’ rival and erstwhile partner, Sir Norman Foster. It will be the North Greenwich Transport Interchange – for the biggest metro station in Europe, for buses departing once a minute, for cars. You don’t build something like that just for a year-long festival. Come to that, you don’t just build the Dome for a year-long festival. What’s the eventual aim of all this?

Like so many Expos and Olympics, the Millennium beanfeast is mostly to do with that dull but vital subject, urban regeneration: the specialist subject of Britain’s former Conservative deputy prime minister, Michael Heseltine. Forget Peter Mandelson, the Minister Without Portfolio who is at present taking all the flak over the project. It was Heseltine who willed the Dome into existence and still officially advises Mandelson on it, with occasional fallings-out. For him, it is a vital part of his vision of an "East Thames Corridor" of new towns, industries and transport links, mopping up the bleak unemployment blackspots of the Thames Estuary. Ever since Margaret Thatcher sent Heseltine in to deal with Britain’s riot-torn inner cities of the early 1980s, this has been his consistent mission. Heseltine presided over Docklands redevelopments, tax-break Enterprize Zones, garden festivals: all regeneration initiatives, aimed at leveraging private-sector funds. The New Millennium Experience is exactly the same beneath all the hype. Moreover it is happening just at a time when, with development pressure on Britain’s countryside once more getting intense, it is becoming politically expedient to find new ways of reviving dead bits of city to build in.