I put it to Smit that Eden is the ultimate old hippy muso's project - geodesic domes, alternative lifestyle scenario, living the rural good life down in Cornwall, the scent of magic mushrooms, the sense of nearby ley lines...I can say this because we have established that Smit and I were at the same University, Durham, in the mid 1970s. He tells me that his self-confessedly awful band played at my college ball. Not that I can remember it, or him, or him me. He was studying archaeology and, let's face it, archaeologists are a different breed to most students. Anyway, we have some kind of shared youth and Smit, once he's established that I have no embarrassing memories to retail, responds vigorously, pointing out that I am wearing an orange shirt and lime-green socks and therefore have no right to hold any opinions on anything. Touche. So we agree that we are both too young to have been remotely hippyish, lament the mostly ghastly state of rock music in that immediately pre-punk era, and re-professionalise ourselves. What, I inquire, of the branding of Eden? What will the name go on to be associated with?

Smit and his financial director Gaynor Coley have been very careful not to franchise the place out. They have turned down some lucrative offers, even when cashflow was worryingly stagnant. They have walked out of rooms where people were waving £400,000 cheques at them. "People have come to like us," he reflects, "because we're not for sale." So you won't find a McDonalds or Burger King or Pizza Express at Eden: they're doing the catering and retailing themselves. "There's no point in people coming here to buy something that's totally unrelated to what's going on," says Coley. To which Smit adds: "It makes no sense. We don't understand why people do go to outside operators. Because if you do, you can't control your own destiny." And he points out the cautionary tale of the Royal Armouries Museum in Leeds, a supposedly privatised institution handed over to outside operators, that has just had to be expensively bailed out by the government.

But Eden - if those half million visitors during the construction phase are anything to go by - will not have a problem attracting visitors. Smit's estimate of 750,000 a year once the enterprise is fully operational may well turn out to be conservative. "There's an element of that old cliche - if you build a dream, then people will come," he says. The Guggenheim Museum in Bilbao, rather than the Royal Armouries in Leeds, is the exemplar he prefers. "So much of our success is down to word of mouth. We haven't paid for an advertising campaign, and we're not going to. It's a waste of time. You want people to talk about you because of your merits. If you have to advertise, you're bloody failing, aren't you?"

Besides, he has a strong feeling Eden is on a roll. "The most moving thing is that dozens upon dozens of people come here, go out onto the viewing platform, and burst into tears," says Smit. "Really, they do. It's very interesting what makes them do that. The fact that it's beautiful is one thing. But one of the common themes is that they love the idea of lots of people working together, creating something fantastic. They find that very emotional. They say that what they find extraordinary about this place is that it's big, but it bears the mark of lots and lots of people. It's intimate, warm."