Once-sleepy Cornwall is abuzz with foodies, celebrities,and extreme sports thrill-seekers. But will success spoil the seaside? Mark Jolly catches the newest wave of Brit chic

You might be forgiven for assuming that this is some sort of trick question. Until recently, even the Brits themselves would have thought you were having a laugh—at the expense of a time-honored tradition of dreary bed-and-breakfasts, soggy fish-and-chips, and trashy bucket-and-spade shops. But not anymore. Cornwall, that serrated spit of southwest England, still earmarked by the European Union as among its poorest regions, has, in just a few brief years, redrawn the map of British tourism.

The changes that have swept this ancient Celtic peninsula come into sharp focus the moment I confront the Eden Project, a futuristic conservatory near St. Austell that has become England's fastest-growing tourist attraction. What floors me as I wander out of the parking lot and gaze down into a galactic crater holding two massive domed greenhouses is the utter un-Englishness of their presence—the sheer audacity of their scale. (The structure is, in fact, the largest freestanding scaffold on the planet.)

"I wanted to do something that was big, really big," says founder Tim Smit, a spirited Anglo-Dutchman who talks with a sort of infomercial gusto, except that he means what he says and believes in his dreams. "I like big—ironically for an environmentalist, because they all say, 'Small is beautiful.' But with Eden I wanted to create that sense of romance and plenty. I wanted the place to look like a civilization. Something that communicated that Jesus Christ, in-your-face element. Something that would make a cynic's jaw drop."

Eden's mammoth interconnecting bubbles rose from an abandoned china clay pit, breathing life into one of the glummest wastelands in this part of Britain. Inaugurated in 2001—the year of foot-and-mouth and 9/11—Eden defied the worst tourism downturn in decades. In its six-month soft opening, during the wettest Cornish winter since 1776 (it poured for one hundred days straight, very nearly destroying the project before it could really get started), half a million paying visitors came to gawk at the creation-under-construction. A registered charity, the Eden Project now receives two million visitors a year and brings in $250 million.

"To be honest, we don't want any more visitors," Smit says, expressing a widely held sentiment among the Cornish, who are increasingly wary of their compatriots to the north—whom they call Emmets, a local word meaning "ants." Why ants? "Because," says my friend Kirsten, who spent her first eighteen years in Cornwall, "there's thousands and thousands of them, and they get everywhere."

Gleefully trumpeted by Fleet Street as the new English Riviera, the Cornish coast now claims some of the finest designer retreats in the land—places such as the Tresanton, which counts Prince Charles and Pierce Brosnan among its repeat guests, and the Nare, which turned away Tony Blair and his entourage rather than give them a discount. Other names from the English celebrity gentry—Hugh Grant, Kate Moss, Jeremy Irons—have simply done the tasteful thing and bought their own Cornish hideaways.