Garden of Earthly Delights

Imagine a giant spider; I'm not talking tarantulas here, but an arachnid worthy of the best 1950s sci-fi movies, one that is as wide as St Paul's Cathedral and as tall as the Empire State Building. Now imagine this creature crawling through the countryside and suddenly coming upon a crater. Slowly it dips its abdomen into the ground, then quietly starts laying its eggs.

This, at first sight, is how the eight interlocking geodesic domes at Eden present themselves. Nestled at the bottom of an old china clay pit near St Austell in Cornwall, these massive structures (the largest is 55 m high, 240 m long and 110 m wide - without any internal support) glisten in the sun like some weird, organic bubble-wrap that is about to pop open and spew forth new life.

The architect behind these strangely beautiful yet otherworldly creations is Nicholas Grimshaw. Despite having designed the Financial Times printing works in London Docklands (1988) and the Eurostar International Terminal at Waterloo (1993), with its sinuous, almost fluid roof, Grimshaw is not yet a household name (unlike Richard Rogers or Norman Foster, both of whom are also 'hi-tech' architects in their own ways). Eden however, will surely change that. Set to imprint itself on the public's imagination rather like the Sydney Opera House or the Guggenheim Museum Bilbao, it will undoubtedly become an architectural Mecca.

The structure's antecedents are not hard to locate if you think about the long-standing English love affair with all things horticultural; an obsession with gardens and greenhouses that blossomed in the Palm House at Kew, designed by Decimus Burton and Richard Turner in the mid-19th century. Although Grimshaw has also undoubtedly been influenced by the work of such great Victorian engineers as Burton, Turner and Isambard Kingdom Brunel (not to mention the American inventor Robert Buckminster Fuller, whose creation of the geodesic dome in the 1930s marked him out as a pioneer when it came to the utilization of basic geometric shapes), Eden is a building for the new millennium.

As such, it draws as much from nature's blueprints as it does from architectural tradition. Its organic shape is akin to the cellular, hexagonal cells that make up a fly's eyes and even the material used to fill each hollowed-out, galvanized steel frame has an organic undertone: the pillows are made of triple-layered ethylenetetrafluoroethylene, which acts like a soft mucous membrane. They are also flexible, highly transparent to a wide spectrum of light, anti-static, resistant to dirt, wind and the weather, and, most importantly, weigh only one percent of an equivalent structure in glass.

So much for the outside then, but what of the inside? Rather like Dr Who's Tardis, once you gain entry, the domes feel even larger than they at first appeared. There are two separate spheres: the Humid Tropics Biome and the Warm Temperate Biome. The former is awe-inspiring, like a cathedral with transparent walls and pews made out of layer upon layer of greenery from Amazonia, Malaysia, Oceania and West Africa. It's replete with a waterfall, a grove of pineapples, palms, vanilla, jade vines, passion flowers, cocoa and the weird Dutchman's pipe. Looking down from above, people move through the misty undergrowth like ants and you can't help but feel that you are in some strange, futuristic dream; or perhaps, like Bruce Dern in the cult sci-fi film Silent Running (1971), you're orbiting Saturn on board a star ship containing the last horticultural specimens from a planet ravaged by nuclear war.

The atmosphere in the Warm Temperate Biome is less otherworldly - the domes themselves are slightly smaller - but by no means unimpressive. This is home to more familiar Mediterranean, South African and Californian species, with olive trees jostling next to grape vines, sugar berries, oranges, lemons and cacti. In fact, Eden can boast over 4,500 different species of plants; in addition, over the next few weeks staff will begin introducing a selection of butterflies, birds and reptiles into each enclosure.

Tim Smit, Eden's chief executive, was a former rock band producer, but more appropriately he was also the power house behind the rediscovery of Heligan (a garden - similarly located in Cornwall - that had been left derelict and overgrown, rather like a horticultural Sleeping Beauty, for over 70 years). With Eden, Smit wanted to 'create the world in a day', a place that will excite and inspire and where we can learn about our planet and how to care for the biosphere, which wittingly or unwittingly we do so much to destroy.

Eden is not supposed to be an exhibition, a museum or, as the brochure succinctly puts it, 'Disneyland with dahlias'; indeed, if this is what it turns out to be, Smit will feel he has failed. With this in mind, jostling alongside the biomes, the restaurants and the Arena there is an education centre, and all the projects will be underpinned by the research carried out by the horticulturists that form Eden's 'Green Team' and the Eden Institute.

In short, Eden is a gateway to the entwined world of people and plants, to our interwoven history, and, from genesis to completion, a revelation of truly biblical proportions.