Heaven and earth

The effete southerner arrives in Doncaster from his air-conditioned Inter-City 225 - a rail-bound cocoon of mobile phones, building society colour schemes, bitter beer for breakfast, inane "customer information" announcements and perilously hot microwave snacks all the accoutrements of the Nineties - to find a town which has had its heart and soul ripped out during those same years.

All but gone are the great coal pits and steel foundries, and the legendary locomotive works that manufactured the "Flying Scotsman" and "Mallard" (the fastest steam locomotive in the world), together with the mesh of light industry woven around them. Over the past five years, nine of the last 10 local pits have closed with a loss of 10,000 jobs. Unemployment is as high here as anywhere in Britain. Only the world-class race-course is still going strong - in fact, it's much improved - and continues to enjoy its annual burst of fame each September with the St Leger.

In return for losing King Coal and locomotive-building, Doncaster has got Leisure. This is writ loud and painfully clear in the form of Doncaster Leisure Park, the largest of its kind in the country, a vast quadrangle of post-modern nonsense that dominates the south Yorkshire town and seems designed to make people spend and get fat. Doncaster Leisure Park is awash with post-industrial ironies: the sons of engine drivers are dressed in ludicrous Casey Jones outfits and employed to chauffeur children on ersatz train rides, and miners' sons shovel seams of popcorn into waxed-paper buckets for chubby "kidz" dressed in Day-Glo leisure-wear from discount warehouses.

In the town, there is a "fun pub" (with miniature theme park attached), a mother of all Asda superstores, one of the biggest open-air car parks in Europe, and brash new suburban housing. In the evening, pubs are crammed with 16- and 17-year-olds, all sporting sleeves that flop fashionably six inches over their wrists; they get tanked up, pile into one of two night-clubs, and start a fight in the pedestrian precinct at two in the morning watched by police cameras installed, 1984-style, throughout the town centre.

Yet, among all these many exhausting leisure opportunities, Doncaster also has something designed to ennoble us. It is one of the most promising of that odd mix of projects funded (half-funded, actually) by the Millennium Commission. Sited on 410 acres of slag excreted from the former collieries, the Earth Centre has been described as Britain's first "green" theme park. Virginia Bottomley, Secretary of State for National Heritage, says it will be "the largest education complex built in the UK since the Victorian museums in South Kensington", adding that "[it] offers the UK the potential to become a world leader in information on sustainable technology".

Fine words, although the project, championed by Jonathan Smales, the Earth Centre's energetic director, nearly ground to a halt earlier this year due to lack of matching funds from private backers: the Millennium Commission will only give half the cost of the projects it supports, which has left many ambitious proposals stuck somewhere in never-neverland. Smales and his team have money from English Partnerships and the EU, but in July were forced to lay off two-thirds of the workforce as the project slipped behind schedule.

When I asked a class of local 15-year-olds what they made of the Earth Centre, their teacher replied that "businessmen are interested in profit not plants, or, if they are, then the sort of plant they mean is big, macho, earth-moving equipment - Bessamer convertors or such". Indeed. 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. 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. "It's a bit like a friendly spaceship that's come to land in the industrial wastes of south Yorkshire," says Smales. "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. We're working with nature, so we have to be patient."

Hopefully, Smales's patience will be rewarded. 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. 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. They will gawp in fascination at the Science and Industry Pavilion, an egg-shaped structure by Will Alsop of Alsop & Stormer. 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. "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. 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. 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. Which is why the Earth Centre will also have its shops and cafes. "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. 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. Smales, however, is gambling that people will see the Earth Centre as an alternative day-out to a theme park. 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". 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. Perhaps they seem worthy; or, more likely, they're difficult to imagine until actually open. Gardens take years, even centuries, to mature, and so will these "green" millennial projects.

Businessmen and local people may not be showing much interest in the Earth Centre, but, when it finally opens, they may yet find it more appealing than Doncaster Leisure Park. And then Doncaster will have an enterprise as exciting in its quiet, unsmoky way as it did when its men were sent underground in cages to dig for coal, and when no one thought of wearing Casey Jones hats - or even knew what "green" or "leisure" meant