Or how two enormous greenhouses have cultivated economic growth in a corner of the country blighted by poverty
Behind the pretty coastline, Cornwall has a bleak economic landscape. The hills are scarred by disused tin and china-clay mines. The fishing fleets are being killed by declining catches, and earlier this year, the attempt to eradicate foot and mouth filled the sky with smoke from pyres.

This visible desolation is mirrored by the economic statistics: Cornwall is one of the poorest counties in Britain, where average weekly earnings are 24% below the national average. Many of those in work are dependent on low-wage, unskilled and seasonal jobs, with little opportunity for security or advancement. Cornwall does not have a major higher education institution. In 1998, when four British regions qualified for European Objective One aid, Cornwall was the poorest.

But look closer. Despite foot and mouth, visitors are still flocking to Cornwall. More and more American cruise ships are docking in the tiny port of Fowey. High-street names are moving into the shopping streets of St Austell. The reason for all this can be found in an old china-clay pit where the science-fiction domes of the Eden Project squat, drawing people to Cornwall in their thousands.

Only three months have passed since the two huge domes of the botanical gardens opened, and already the £75m project is having a profound regenerative effect on the local area of Restormel, south Cornwall. Cornwall's tourist office says that accommodation in the region is fully booked until the end of August, and many hotels are booked until Christmas. In April, unemployment dropped 0.8% in the region, double the average for the South-west.

Many businesses in nearby St Austell say they are feeling the "Eden effect". Operations manager for the project, George Elworthy, says the organisers always intended Eden to benefit local business by sourcing its needs locally. He says: "We opened when the foot-and-mouth crisis was at its height, which sent out the message that Cornwall was still open for business. This meant we gave a bigger boost to Cornwall than anyone had imagined."

The Eden Project's success has surpassed all expectations. Last year, more than 400,000 people visited the site before it even opened. And since its official opening in March, some 500,000 visitors have poured in. According to a spokeswoman, the project is set to easily exceed its projection of 750,000 visitors in one year. She says: "We still have the summer to go, and around 2 million people will have visited by next March."

Just as the Frank Gehry-designed Guggenheim Museum in Bilbao injected new life into the run-down Spanish city, Eden is changing the face of south Cornwall. Both projects attracted attention because of the design and technical innovation involved, turning previously little-known places into tourist hotspots.

Such has been the effect of the Eden that Cornwall is one of three regions chosen by English Heritage and the Commission for Architecture and the Built Environment – along with Lincoln and Sheffield – for assessment by the government's regeneration advisory panel on the impact of modern architecture on the economy and community.

Cornwall has benefited both from the visitors and profile arriving with the Eden project and the arrival of £300m Objective One funding. Cornish local authorities have until 2006 to allocate the funds, which must be matched by UK public money, making a total of £600m. "All sorts of projects are now possible," says Stephen Bohane, manager for the Cornwall region of the SWRDA.

Visitors are flocking to Cornwall. More and more American cruise ships are docking in the tiny port of Fowey. High-street names are moving into St Austell

Already, Eden and the Objective One funding have been driving rural regeneration, creating an environment that encourages major ambitions. One such is the SWRDA and Restormel Borough Council plan to build a £90m centre that could one day become Cornwall's university. The project was awarded a £19m government grant in May, and will be based at Tremough, Penryn.

At Eden, planning permission is awaited for the third greenhouse, which will feature a dry tropical climate. The 10,000 m2 biome will be constructed by the Alfred McAlpine/Sir Robert McAlpine joint venture team that built the original centre. This team, along with Eden architect Nicholas Grimshaw & Partners, is also set to build a £1.5m educational resource centre, although funds have yet to be raised. A feasibility study for a 200-bed hotel – designed again by Nicholas Grimshaw – is being carried out.

In St Austell a £40m scheme to transform the shopping centre won approval last month. David Rust, chairman of the St Austell Chamber of Commerce, says that Eden "has, without doubt, encouraged high-street names into St Austell".

The council has chosen developer David McLean Group to lead the project, with designs by Angus Meek Partnership and Chapman Taylor Consultants. The SWRDA has also asked McLean to tie the town more closely to Eden. "We have directed the developer to fully exploit the town's link to Eden. We will be looking to see more bars and leisure facilities put into St Austell," says Bohane. Pub chain JD Wetherspoon and retailer John Lewis Partnership have expressed an interest in moving there.

The SWRDA and Restormel council are also conducting a feasibility study into a multimillion-pound revamp of the A391 main road that connects St Austell to Eden, another idea to strengthen the infrastructure around the attraction.

Enterprising individuals see scope for making money. Taxi firms are also seeing more business. Steve Milhan of St Austell Taxis has seen custom grow by about 15% since Eden opened and he expects to get busier still. Business is booming for John Hallett, manager at the Pennwinnick Road service station just a few miles from Eden. Petrol consumption is 30% higher than last year and he sold 97,000 litres last week. Local estate agent David Lapping of Mary Wether & Graves says that enquiries about bed-and-breakfast establishments, or properties suitable for conversion, have shot up by about 70%, pushing prices with them.