There’s also the Middleton Botanical Gardens in west Wales, and the Millennium Seed Bank (wonderful name) which will house 25,000 species of British and foreign flora in an outpost of Kew Gardens in leafiest West Sussex.None of these has attracted much in the way of newspaper headlines. They will come away not just smelling of popcorn and burgers, but with real insight into how we can each nurture our planet.There are other Millennium projects that take “ecology” as their cue, including a Garden of Eden, sunk into a deep quarry in Cornwall, which has been designed by Jonathan Ball, a local architect, and Nicholas Grimshaw of Waterloo International Terminal fame; it’s a walk-through sequence of micro-climates from around the globe contained in a colossal, Dan Dare- style “earthship”. Smales, however, is gambling that people will see the Earth Centre as an alternative day-out to a theme park. The Centre for Alternative Technology in Snowdonia is an outstanding example of a small project, pioneered by enthusiasts, that has developed quietly and responsibly over the past 25 years. “We have to provide these things,” says Smales, “partly because people have come to expect them, partly because they can be very profitable, and because we will be running the Earth Centre on commercial lines: it must earn its keep without having to rely on external funding.”Other ecology centres, built on a much less ambitious scale, do pay their way with little in the way of commercial activity. Which is why the Earth Centre will also have its shops and cafes. It is working on a “close-to zero-energy” transport system (possibly powered by water) to link the futuristic pavilions with the existing railway station at Conisborough, which connects in turn with the mainline station at Doncaster a few minutes away.But even plants and an intensive course in ecology may not be sufficient bait to woo visitors in their hundreds of thousands to the edge of Doncaster.

We plan an Earth Centre office which we want to make the `greenest’ anywhere.”Before these radical buildings rise from what were, until very recently, slag heaps, the Earth Centre people are clearing the River Don which flows through the centre of the site, planting thousands of trees, and building a comprehensive range of small greenhouses and sheds in which plants, endangered or thriving, will grow. “People go to Kew Gardens,” he says, “not just to look at plants, but because they love going inside the famous Palm House and Temperate House.” His buildings, he continues, “will use very little energy, and will point the way to new forms of design for the 21st century. They will applaud the Planet Earth Pavilion, designed by Peter Clegg of Fielden & Clegg, which will grow out of a hillside and be made of rammed-earth and limestone.Smales suggests there is a precedent for the Earth Centre’s heavy investment in seductive new buildings. They will gawp in fascination at the Science and Industry Pavilion, an egg-shaped structure by Will Alsop of Alsop & Stormer. At the heart of the Earth Centre, visitors will discover and – I guarantee – marvel at the great conservatory being designed by Amanda Levette and Jan Kaplicky of Future Systems. If Doncaster no longer produces innovative engineering as it did in the heyday of the Great Northern and London and North Eastern Railways, it is about to give birth to some of the most innovative buildings in Europe.

We’re working with nature, so we have to be patient.”Hopefully, Smales’s patience will be rewarded. “I can understand why people are a little puzzled by what we’re up to, particularly, I suppose, because we have a lot of land to reclaim and, because of this, no exciting buildings to show or anything else, really – not yet, anyway. “It’s a bit like a friendly spaceship that’s come to land in the industrial wastes of south Yorkshire,” says Smales. What, they ask, are Smales and his gang of botanists, ecologists, architects and scientists doing with the pounds 125m they have raised?But when completed in 2005, the Earth Centre will be an extraordinary place. Although the banks have lent money, their executives talk about “marketing strategy and advertising spend”, and about a highly profitable retail centre, rather than the future sustainability of the planet.Perhaps such concepts seem pie-in-the-sky to south Yorkshire folk; certainly, in the pubs I went to, the Earth Centre drew little favourable comment, perhaps not so much because people are against it – the local press reports the standard line of “what’s happening to all the cash being pumped into the so-called Earth Centre?” – as because they are mystified by a grand plan which promises to make slag profitable.