Could this be the Bankside of the North?

Once Europe's biggest steel melting shop, Templeborough closed in 1993 and has sat idle ever since. But that is set to change next year - thanks to a bold attempt to breathe new life into the defunct Yorkshire mill by turning it into a monolithic, multimedia educational tool.

The eye is drawn inexorably upwards and remains fixed on the compelling detail of the vast vault - too complex to make sense of, and yet strangely and delicately seductive. The interlocking traceries of hundreds of steel trusses and joists, the gantry spars and pillars coated in algae of rust; and all of it fading into a velour of darkness 100 feet above. Shards of sepia light fan down from breaks in the roof. Dust hangs in the air like musty incense.

The eye is drawn inexorably upwards and remains fixed on the compelling detail of the vast vault - too complex to make sense of, and yet strangely and delicately seductive. The interlocking traceries of hundreds of steel trusses and joists, the gantry spars and pillars coated in algae of rust; and all of it fading into a velour of darkness 100 feet above. Shards of sepia light fan down from breaks in the roof. Dust hangs in the air like musty incense.

At ground level, the vista across the mill floor is a graveyard of dead weights: blockheaded steel forms and round shouldered hulks brought to an earth that no longer wants them: 20ft high scrap metal ladles; racks of control panels; giant scrap-magnets; huge six-inch thick steel pots where scrap was reduced to seething red heat by charred electric probes whose scintillating amperage could have lit up the whole of Huddersfield.

This once great industrial cathedral between Sheffield and Rotherham was born of the need to produce an endless supply of artillery shells to rain down on the Boche. And so, as it stands, Templeborough steelworks - originally Steel, Peech and Tozer - would now seem to be the graveyard of three generations and thousands of families' worth of aspiration which began in 1916 and was finally vaporised by the white heat of international competition more than seven decades later.

In 1970 it was Europe's biggest steel melting shop, with 10,000 working round the clock in three shifts as part of a linear development of linked mills that stretched almost continuously for the best part of a mile. Thirty years ago, locals found it hard to squeeze into the No. 69 buses that chuntered past the factory between the two towns because they were jam-packed with thirsty workers coming on or off shift, men who barely noticed the first two pints of bitter - "dust-slackeners" - going down in the Temple pub in Eakin Street.

At night, sections of the mill's galvanised outer skin, particularly around its so-called great hall, glowed red. It was the hearth and absolute heart of a community where stainless steel had been pioneered in 1913; an organ whose blood gouted from the lips of furnaces at more than 1,500C, to be cast into ingots, rolled steel, tank turrets, railway wheels.

The mill, almost 400 metres long and considerably bigger than the ex-Bankside power station which houses London's Tate Modern, shut down in 1993; only one of its six electric arc kilns was operating by then. But, like Bankside, this is a comatose Gulliver poised to rise again in a bold vision driven by the charitable Magna Trust. The £37m project is reinventing Templeborough - but not for art's sake.

Magna, armed with Millennium Commission funding gained by Rotherham Borough Council, and EC grants, is fashioning a monolithic multimedia educational tool whose messages will be derived partly from the history of the mill and, more specifically, from the elements that once fuelled its success: earth, water, fire and air.

In architectural terms, Templeborough will do a Bankside: design and form inserted into an existing space without compromising its atmosphere. But, unlike Herzog and de Meuron's highly controlled Bankside solution - half tidily gutted power plant, half art galleries with a block of light-beam icing on the top - Magna's architects Wilkinson Eyre will let the public see virtually all of Templeborough's structure as it was, tonnages of detritus and all: the building's shell and its contents will remain much as they were left at close-down seven years ago.

Chris Wilkinson and project architect John Coop are plainly besotted with the challenge. The pair have become willing supplicants to the history of the mill, and to the perceived cultural requirements of the local community.

The enthusiasm and boldness they've brought to the project is founded on the raw, no-frills power of the building - the seemingly endless volume of its space, the thousands of tons of steel engineering and equipment whose mute presence delivers such a stunning punch to the senses and, crucially, to the imagination. "It's important for us not to bugger up the building," says Wilkinson. "The quality of the building - the soul and spirit of it - must be kept."

Their solution to the science-adventure experience required by Magna will therefore be dramatic, but deliberately minimal in scale: four pavilions linked by walkways and lifts, set on different levels in Templeborough's great hall, representing the key organic elements; and in each, displays and interactive sections conjured up by Event Communications. The pavilions will take up relatively little space: any attempt to upstage the great hall would have been both futile and tasteless.

"We view the building as a post-industrial landscape," explains Coop. "It's on such a scale. There's a real tension, the brutality of it - it's hell's kitchen. Our path through the building and the locations of the pavilions reflect the steel-making process. It's a journey through time, a very physical experience."

And intimate, according to Wilkinson. "We're trying to keep the story going, and there are several stories being told. One is about the steel working process, which you kind of imbibe. It's subliminal. You'll go away knowing how steel is made. And it will be a story of this particular building and the lives of the workers. I get the feeling of the Holocaust - people falling into the vats and being vaporised. It's really lurid. It was their lives."

Wilkinson says the community's relationship with Templeborough was of the love-hate variety: The workers, he says, "found it terribly dangerous, but they found it exciting. It drained them. They were given salt pills and beer vouchers. I don't normally talk in such an emotional way about buildings - but this is more than just a building. Everybody who goes into it feels it. It's a staggering building, a very powerful space, and dark ."

Coop sees Templeborough as a kind of giant Tardis, a place "where it's like going into a dream, and we're capitalising on that. We're painting the whole building black. The building will act as a sign". And one that, as Wilkinson suggests, highlights a developing strand in architectural thinking.

"We're getting to the stage in modern architecture," Wilkinson says, "of getting past the brutal and the banal. People are feeding in more complexity - not so much veils of deconstruction but intellectual understanding."

The design of the four elemental pavilions reflects this approach - a search for reactions that are both visceral and mentally stimulating. The earth pavilion, for example, is being set into the remains of the deep cellars where the slag pots were emptied into trains. From here, tunnels once led to the mill's main office, hospital and sample-testing unit. Visitors will descend through up-flung steel fractal-plates into a seismic earth zone.

The water pavilion is an asymmetric spiral wave - a kind of ghostly last tango for Sheffield which, at the start of the 18th century had 150 water mills, the world's most intensive concentration of water power. The fire pavilion will offer simulated furnace conditions and genuine 15,000 volt lightning strikes; and the air pavilion - the first encountered by visitors after passing through Magna's introductory mill-history section - will be set in an apparently floating translucent dirigible.

Magna must pull in at least 250,000 visitors a year to cover its £1m-plus annual operating costs and chief executive Stephen Feber hopes that his vision can unlock the imaginations of young people in the region - and release the pent-up memories of those who once worked at the mill.

He pushed Wilkinson Eyre to the limit, turning down their relatively safe early designs for the elemental pavilions - "I said, 'well, this isn't very funny', and encouraged the architects to produce more striking forms. And back came this extraordinary airship and this amazing steel wave." Feber considers the result "a whole composition. Too often, these projects have an art gallery mentality - art galleries as containers".

He cites "philosophical and pedagogic themes" and "visceral emotional things" as the roots of his vision. He aims to create "an informal centre with a real-world context. It allows us to talk about structure and the making of things. Too often, we obscure the process of making things".

The informality he talks of will be a key element in Magna's educational approach: "We all learn in different ways. We all have different cognitive signatures. But learning by doing, with multiple points of entry, is a way to do it."

There is a growing hoard of material - ranging from tool-cutters to poems - offered to Magna by ex-mill workers. One of them is Keith Billington, whose three generations of family clocked up a collective 500 years at Templeborough. He entered the great hall for the first time after national service. "I thought it was something special," he recalls. "It was that big and that awesome and that frightening. If Stephen Feber can get that, and get the respect for the building, Magna will work."

When Magna's first visitors enter Templeborough's great hall early next year, they may get more. They may feel an obscure tingle; something of the same sharp prickle that Keith Billington and his shift-mates felt when, with a jolting, crackling flashover, the electric probes hit the scrap metal in the melting pots and radiated such a surging electromagnetic pulse that the hairs on their arms stood up as stiff as wire.

ROADS TO SALVATION

English heritage has given Grade I listings to more than 150 at-risk industrial buildings dating from the 18th and 19th centuries. But the conservation of the bricks and mortar of the industrial revolution, which only began in earnest in the Eighties, remains an acutely difficult challenge.

Despite the injection of more than £65m from the Heritage Lottery Fund since 1997, the sheer scale of these key sites and their buildings alarms many potential redevelopers or conservation groups: the cost of repair and maintenance is typically high.

Anthony Streeten, secretary of English Heritage's industrial architecture panel, takes an upbeat view. "These buildings are robust and they've got genuinely useable space," he says. "There's definitely more of a picture of optimism here.

"If we can get the right people together and the right funding streams, they're capable of salvation."

Redevelopment may be the best way forward. Though visits to industrial heritage sites had increased by 21 per cent to 4.4 million by 1997 - due to more sites becoming publicly available - the numbers of visitors per site has fallen.

Most of English Heritage's at-risk Grade I industrial buildings remain either unoccupied or in the process of being renovated or redeveloped, but key success stories support Streeten's longer term hopes.

Starting with English Heritage's intervention to save the Ribble viaduct on the Settle-Carlisle railway line 11 years ago, other "salvations" under way include Arkwright's Cromford Mill in Derbyshire and the mile-long Rykneld Tean mill complex in Derby.

*The International Committee for the Conservation of Industrial Heritage is holding a millennium congress in London from 30 August to 3 September.