In the summer of 1958, I left college and shipped out for the Orient as a merchant seaman earning $80 a month aboard a tramp freighter sailing under the Liberian flag. That same summer, my Harvard classmate K. Khan, then known to the rest of the world as Karim Aga Khan, shipped out aboard his yacht. Legend has it that he then discovered what would become the Sardinian paradise of the Costa Smeralda when he took refuge from a Mediterranean blow in one of the island’s nameless rocky coves. I don’t know what K. earned a month. I do, however, remember photos of his enormously corpulent grandfather, the third Aga Khan, being counterbalanced on a giant scale by his weight in gold and diamonds, a gift offered up by the Ismaili Muslim sect that he presided over as spiritual leader. K. bought a 14-mile-long strip of northeastern Sardinia’s coastline and by 1963 had put together a consortium that created out of whole cloth one of the world’s most exclusive playgrounds, christening it for the emerald clarity of its waters. My friend Alberto was nearly as prescient. He first came to Sardinia with his motorcycle in ’63 and has summered (and sometimes wintered, springed, and falled) there ever since. Today, he and his wife, Giovanna, have a little house near Porto Cervo, the wildly exclusive hot center of the Costa Smeralda. And he’s traded in his camper for a metallic-yellow, 550-horsepower, 207-miles-per-hour Lamborghini Diablo 6.0 that we shared for a tour of this stunning island playground of the European upper crust. Everyone who’s anyone here has his own place; my base is the celebrity-packed, peerless, and dizzyingly expensive Hotel Pitrizza, on a narrow bay just west of Porto Cervo. It is a small, low sprawl of white granite villas roofed with thick sod, stone, and plantings, invisibly irrigated to produce a perfume-clouded profusion of shrubs and blooms constantly aflutter with butterflies. In the bay, a motor yacht so huge that I at first mistake it for an Italian frigate drops anchor. At night, when I don’t bother to trundle closed the terrace door and its heavy wooden shutters, the beam from a distant lighthouse dances across the wall in quick, silent bursts.

Day One: Cala Gonone—251 Miles

The $275,000 Diablo is a car as spectacular and alluring as the bronzed starlets who frolic in the surf here, but on the Costa Smeralda, this beauty is met with cool indifference. “Here, the show is with boats,” sniffs Alberto. “No—ships, actually. One Arab comes here every summer with two yachts. One is two hundred feet and the other, for the servants, is about a hundred. He rents two dock slips for sixteen hundred dollars each.” “Wow, thirty-two hundred dollars a week?”

“A day. And his wife likes to go shopping, so he has two slips in the new port and two in the old port, a quarter of a mile away, where the stores are.” Boy, are they ever: Cartier, Gucci, Versace, Prada, Dolce & Gabbana, Loro Piana, and the rest, in a multilevel piazza jumble as artificially weathered and island-styled as a film set. The only empty storefront is evidence that Ralph Lauren found himself way out of his element when he set up shop here. It is early June, yet the roads are untrafficked as we rumble south toward Nuoro. Sardinia is one of the world’s great examples of the joys of off-season travel. July and August are hot, oppressive, and jammed, for even the superrich travel in a herd. May finds Sardinia at its most spectacular, with the island in bloom everywhere; late September finds it empty, while the air and water are still summer warm. Go figure. The highway toward the south is a divided four-lane, and the Diablo lopes along at an easy 110 miles per hour. (Its top speed, 207, is one that few light planes can equal.) Although it hasn’t rained since March, suddenly it pours. “You are one of the only Americans ever to have driven a Lamborghini in the rain,” Alberto teases, remarking that moneyed Europeans treat such $300,000 exotics as daily drivers, while we Yanks consign anything rarer than a Jaguar to the garage at the first sign of a sprinkle. Sardinia’s terrain is almost North African, an intensity of oddly eroded granite and scrubby shrubs, vivid oleander and bougainvillea. The northern part of the island is a huge lump of rock barely scabbed with a 20-inch layer of sandy soil, and few but the hardiest shepherds and fishermen had been able to make much of a living here until the tourists came. Near Nuoro, a side road that slows the Diablo to less criminal speeds leads us to Dorgali, flush with local artisans, and then, on a primitive two-lane boring through the rock of a mountain wall, to a spectacular view of . . . well, the top of a roiling rain cloud. Alberto assures me that far below is the little harbor of Cala Gonone and one of the more spectacular vistas in Sardinia: juniper-shrouded limestone hills descending to the emerald Mediterranean. Perhaps some other time. Heading home along the narrow coastal road after a long Italian lunch, I glance into the mirror to see a Smart sniffing our rear bumper. The Smart is a European microcar of the size and grace of a Porta Potti and made from much the same material. We laugh at the absurdity of finding ourselves in the world’s fastest and most powerful car, being hounded by some joker in the world’s slowest mobile latrine.

Day Two: Maddelena Archipelago—44 Miles

To have a Lamborghini at my beck but to choose to travel by boat instead? Only a yachting playground as varied and spectacular as the clutter of islands off the Costa Smeralda could tempt me. “We’ll have a quick lunch and go,” says Alberto. Two hours later—fast food Italian style—we stumble out of the casual Gastronomia Belvedere, above Porto Cervo, and head harborward. Once we’re aboard his twin-engine 25-footer, idling out toward the breakwater, Alberto points out a low white house overlooking the harbor mouth. “It is the Aga Khan Karim’s,” he says. “All the shades are drawn, which means he’s not here. Even when his son or daughter are in residence, the shades are kept closed if the Aga Khan Karim is away.” Garibaldi lived—and died—on nearby Isola Caprera, where today his house is a museum. A swashbuckler, mutineer, cowboy, guerrilla, and admiral, he was Butch Cassidy, Indiana Jones, and Rambo, all rolled into one. Mercifully, he never dreamed that his beloved Casa Bianca would one day be next door to a Club Med. We pause briefly in sight of both, in a cove where one other boat swings from an anchor line and a sunbather on a float seems to levitate ten feet above the seafloor on the crystalline water. “You can’t even think of getting in here during the season,” Alberto says. “In August it is unbelievable. At 11:30 every day, it’s like a big boat race, with a thousand boats trying to get out of Porto Cervo at the same time. At 5:30 they all rush back in again.” I guess even the superrich aren’t immune to traffic tie-ups. A friend of Alberto’s has a villa right on the beach at Isola Santa Maria, where we pause to skinny-dip. “It is lovely, but you see how his veranda looks like a bar?” Alberto asks, pointing. “During the summer, tourists keep coming up and demanding a drink or to use the toilet. I tell him he should take the Costa Smeralda attitude and say, ‘A Coke? Of course. That will be ten dollars, please.’ ”

Day Three: Along the Coast to Alghero via Castelsardo—242 Miles

Rigidly defined, the Costa Smeralda is a Disney village for the rich within which arbitrary architectural, ecological, and economic standards are enforced. So much so, in fact, that the Aga Khan—who established the standards—has sold his consortium interest, furious that the regional government has scuttled his development plans, which included three more golf courses (currently there is only one). Beyond the limits of the Costa, however, development is unrestrained. “They are overbuilding, destroying,” gripes Alberto. “These hotels, they could be anywhere—Mexico, California, Hawaii . . .” Everywhere I turn there is the gaunt, towering rock, so eroded that it looks more like sandstone or frozen mud. At Capo Testa, where Corsica looms only half a dozen miles away, there’s a huge tumble of stone rising from the sea. “Thirty or forty feet under the water, you can still find big pink-granite columns, partly cut,” Alberto says. “The Romans took them from here for their monuments. The ships that sank are gone, but their cargo remains.” Heading southwest toward Alghero, I finally get a reaction to the Lamborghini when we stop for espresso, the fuel Italians guzzle more impressively than the ten-miles-to-the-gallon Diablo does gasoline. Far from the Costa Smeralda, a young man kisses the gathered tips of his fingers when I open the hatch to reveal the engine, an aluminum lump large enough to pull a commuter train. I have the feeling that he’d fall to his knees if it wouldn’t then obscure his view of the gleaming 12 cylinders. Our tanks full, we head south to Castelsardo, one of the only spots on Sardinia that offers the tourist holy trinity of castle, cathedral, and handicrafts (mainly woven basketry). Of the three, the castle is the most immediately impressive, capping the town like a huge rock toque. It was originally built in the twelfth century by the Dorias, the powerful Genoan dynasty, during a time when Sardinia was simply a way station for warring Spaniards, Genoans, and Piedmontese. From the small harborfront of Alghero, many-seated motorboats make the half-hour run to the Grotta di Nettuno, the area’s prime tourist attraction, but we have driving to do—the long run home through the Sardinian interior. It’s a much harder, drier land, but the road, which has never felt frost, is high-speed heaven, at times even four lanes. I give the Lambo free rein, and the cockpit fills with the wail of gears and the hoarse bellow of the engine. In a car that accelerates from zero to 120 in less than 12 seconds, passing is a game that can be played almost anywhere . . . except on the winding road I finally take north from Olbia back to the Costa Smeralda, which seems to be getting more crowded by the hour. There’s a lot to be said for life in the fast lane, especially at the wheel of what is arguably the world’s most extreme car. But back on the Costa Smeralda, I can’t help slowing down to take in my last glimpses of this rarefied resort—at a leisurely 95 miles per hour.

Pit Stops

Lodging

The Hotel Pitrizza is the Costa Smeralda’s toniest. There are only 38 rather small rooms and 13 grand suites, all in ground-hugging villas ripe with blooms and shrubbery. The reward is the quiet elegance and personal attention you’ll find, the secluded beach, and one of those edge-of-the-world swimming pools you normally see only in, well, travel magazines (800-325-3589; www.luxurycollection.com; doubles, $640–$1,020, including breakfast and either lunch or dinner). The original—and still champion—Costa Smeralda palace is the Hotel Cala di Volpe. Like a Gaudí fantasy, it’s a structure with surprises everywhere—a combination of a huge farmhouse and a folly castle, each room painted and decorated in a different style to keep your head swiveling (800-325-3589; www.luxurycollection.com.; doubles, $570–$1,040, including breakfast and either lunch or dinner).

Dining

A dinnertime favorite among Porto Cervo locals is the Ristorante Gianni Pedrinelli. Specialty of the house ($20): baby pig roasted over an open fire for six hours (39-0789-92436; entrées, $7–$22). Twenty miles south, in Olbia, is the Ristorante Gallura di Rita, which also has ten simple bedrooms. You’ll need one after five courses of what some claim is the best dining in Sardinia (39-0789-24648; entrées, $25–$39; doubles, $59).

Behind the Wheel

The myth is that industrialist Ferruccio Lamborghini, who owned a Ferrari, was once insulted by Enzo Ferrari and retaliated by establishing an even better line of V-12 Italian sports cars. The truth is that one day in 1960, the chief mechanic in Ferruccio’s tractor factory dropped two clutches on his boss’s desk. One was from a Lamborghini tractor and cost $50. The other was from Ferruccio’s own Ferrari, which the mechanic was repairing, and cost $500. They were otherwise identical. On that day, Ferruccio Lamborghini learned the principle of value-added manufacturing. Today, Lamborghini (now owned by Audi) manufactures the world’s most extreme sportster, a $275,000, 550-hp, two-seater coupe that it claims is—in the limited-edition GT form—the world’s fastest production car, capable of 235 mph. The standard version that I drove is capable of only 207. Pity. Is a Lamborghini Diablo better than a Ferrari Maranello, its competitor’s current V-12 485-hp, 188-mph, two-seat, quarter-million-dollar coupe? That’s like asking if jazz is better than swing, if Heidi Klum is more beautiful than Cindy Crawford, if fine scotch is better than great bourbon. They’re . . . different. Ferraris are fast, powerful, visceral, and refined. Lambos are fast, powerful, visceral, and brutish. “Ferraris are civilized and so are their buyers,” says one Lamborghini spokesman. “Our car is the most extreme car in the world, and our buyers are from show business and sports—people who aren’t afraid to be noticed.”

And noticed you will be, in a car that sounds like PT-109 on the prowl and looks like a Ridley Scott prop. So extreme is its shape that although the original Diablo was introduced in 1990, it’ll probably be another ten years before anything will trump it. If you want a comfortable, convenient, spacious, quiet ride, go out and buy yourself a Porsche. If you want a car that most people mature enough to afford would consider completely over the top, consider a Diablo.