Thus the Dome, which could have been built anywhere, is on what used to be a poisoned industrial peninsula. Soon, where the chemical bulk tankers used to dock, there will be an £80m cruise ship terminal, complete with hotel and pricey apartments, funded entirely from the private sector. Alongside this, just downstream of the Dome, will be a large new "urban village" – another favoured Heseltine concept. Consortia of housebuilders and architects are at present competing to build it.

Why should cruise liners stop here? Why, because it is handy for historic Greenwich with the National Maritime Museum (also being revamped for the Millennium), the Royal Naval College, the Cutty Sark, the Royal Observatory, the Queen’s House. Visitors will take the new Jubilee Line right into central London. There might even be a fair bit of continuing tourist trade to the Dome – were it to become a sports arena, a concert hall, or just a vast exhibition and conference hall. It’s designed to last a minimum of 25 years. And once you’ve got all that, you can depend on the private sector rushing in to open restaurants and shops and build more apartments: wherever people gather in any numbers, developers will cash in.

Then again, the Year 2000 "Experience" may be such a washout that everything is stopped dead in its tracks. But that is unlikely, however bad the contents of the Dome. Ask anyone who’s been to an Expo what, exactly, was in the pavilions. They can never remember. It’s the going that counts, the buildings that are remembered. The Great Exhibition of 1851 was the spur for the building of London’s great museum, music and university district of South Kensington. The 1951 Festival of Britain left the permanent legacy of London’s South Bank arts quarter, now rapidly reviving in partnership with the private sector. The Millennium Dome has a similar underlying agenda. Whether the events of the "Experience" are a hit or a miss, it is on the cards that by 2001 the British will have good cause to celebrate: not Mandelson, but the unlikely pairing of Rogers, the New Labour architect peer, and Heseltine, the out-to-grass Tory grandee.