There's a wave of travelers who are making do with less—deserted islands, silent retreats, anti-smoking cruises. Has abstinence become the new indulgence?

Karen and Jeff Block were looking for a place to celebrate their 15th anniversary last November with 40 friends. They considered high-end options such as Mahakua, the Amanresort in Mexico, but found them not quite right—they wanted something unique. Even Costa Rica or surf camp sounded too predictable.

Instead, they gathered at Hotelito Desconocido, a Mexican ecoresort where there's no electricity. It was a revelation. The lack of modern amenities felt like an opportunity to see the world differently: they read by candlelight and hosted beach barbecues and bonfires. "You can go anywhere and stay at a nice hotel and be saturated with luxuries," says Karen Block. "But at Hotelito, you realize you don't need all that. It's about the beauty of who you are and who you're with." Indeed, when her sister went to the Four Seasons Punta Mita afterward, she found the air-conditioning and marble bathrooms distracting.

For years, hotels and resorts have poured on the excesses. Pillow menus, bath butlers, pet concierges. Even spas have shrugged off asceticism in favor of indulgence—they're as likely to serve wine as not. But every trend brings a countertrend. Call it the deprivation vacation: travelers who can afford to stay at a Canyon Ranch or a Ritz-Carlton, thank you very much, are seeking out places where they get less for their money. (integral)

Authenticity is the appeal for much of the less-is-more crowd. Vladi, a company that sells and rents islands all over the world, peddles a $250 survival kit: designed by Patrizia Gucci, it holds a two-person tent, a fishing rod, a hammock, and a magnifying glass. It's bought primarily by people who own undeveloped islands; they want that Robinson Crusoe experience, the kind you won't find at a resort in Fiji where there's always a pool boy skulking around. Those who can't afford to buy their own island can pay $165 a day to rent Sleepy Cove, near Halifax, Nova Scotia. Popular with upscale urbanites looking for simplicity, it has a rowboat, canoe, and one log cabin. In Tasmania, the hot hotel is the Bay of Fires Lodge, deep in a national park. You not only have to hike 15 miles to reach it (with an overnight campsite stay en route), but you have to pump your own shower water once you'rethere. Guests don't just put up with the hassle, they embrace it as part of the experience. At least at Bay of Fires, you get a shower: students at Boulder Outdoor Survival School, in Utah, are left in the woods to fend for themselves (though guides follow surreptitiously to ensure their safety). School owner Josh Bernstein says there's been an uptick in the number of city dwellers who've never been camping but are nonetheless attracted to the idea of learning how to "cut the umbilical cord."

It doesn't get much more real than that, unless you do it in Africa. In addition to high-end safaris, the Colorado-based outfitter Explore Inc. has started specializing in edgier experiences—such as a $9,000 trip to Niger that owner Cherri Briggs calls "seriously minimal and very hard." This can mean lying in a camel trough to cool down in 140-degree heat or finding a spring to do your own laundry. "If you went in a more luxurious way, you wouldn't be able to interact with the locals properly," says Michael Fitzgerald, a serial entrepreneur who's taking his 14-year-old nephew on the trip. And interact with the Tuareg people they will: Explore not only hires native guides, but also has them organize a festival with hundreds of tribe members. The safari-goers will be sleeping in nomadic tents.

"Depriving yourself is a perfect anti-materialist, anti-affluence gesture," says David Brooks, who tracked the lifestyle of "Bourgeois Bohemians" in his book Bobos in Paradise. "People like to vacation among those who have the lives they're too ambitious to lead themselves. Whether it's Tuscan peasants who know their mushrooms or back-to-nature ranch hands at dude ranches, they seem to be leading honest, simple, more virtuous lives—not that any of us would actually want to live that way."

For others, authenticity and simplicity have nothing to do with it: they just can't trust themselves. Carnival has a smoke-free cruise ship, the Paradise, and if you're caught possessing a cigarette, you'll be kicked off at the next port of call, hit with a $250 fine, and forced to figure out a way home. For some, the threat of a week trapped on a ship with a bunch of people undergoing nicotine fits might be reason enough to quit; others might worry that the buffet-laden cruise ship would be fraught for anyone fighting an oral fixation. Travel Companion's Doug Payette, the travel agent who persuaded the American Lung Association to endorse the program, says it doesn't matter: "The average consumer who goes on a cruise gains five pounds anyway!"

In which case, they might sign on for the new wave of fitness trips. New York gym chain Equinox is now running exercise getaways—lounge on the beach and work on your abs, too. A pioneer of sorts, David Kirsch, of Manhattan's tony Madison Square Club, has held fitness "boot camps" in Costa Rica, Turkey, Telluride, and, most recently, Capri, where he rented a villa and brought in a private chef. Kirsch's wards lost 5 to 10 pounds on a diet of no pasta, no bread—and no biscotti. Did they complain?"All the time!" says Kirsch. "The trick was not depriving them so much that they couldn't last more than two days. We'd go to the Quisisana hotel every night and have one drink. It's not like the ashram where you're eating tree bark."

Kirsch is joking about the tree bark, but California's Ashram is a legendary spot for dropping weight fast. Spa-goers are put through a rigorous exercise regime and fed little more than a glass of orange juice at breakfast. Brazil's Body & Soul Adventures was initially affiliated with the Ashram; the spa is now on its own, but the only-what-you-need philosophy remains. Guests spend a week on the island of Ilha Grande, where they're put through a brutal regimen of hiking, kayaking, and yoga and are fed 1,200 calories a day. You try hiking for four hours and then having an egg with carrot and celery sticks for lunch. "By the end it feels normal," says Jessica Shaw, a magazine writer. But does it feel good?"You're kayaking and your arms are like jelly, but then you get to a breathtaking beach and think, 'Thank God I came on this trip.'"

Shaw points out that it's easier to savor deprivation as long as you know there will be indulgence in the end—which explains her group's binge of a dinner in Rio at the conclusion of the trip. What did they eat?"What didn't we eat?" she says. "Eight thousand rolls, two desserts each, the entire appetizer list, wine...." Body & Soul admits that now and again someone tries to sneak in a Snickers, and it's evidently not uncommon elsewhere. Rita Rivest says first-timers have been known to fortify themselves in advance of coming to Sage Hill, her well-being retreat in Ojai, California, where there's no meat, alcohol, or wheat. Rivest uses car services to bring guests to the retreat, and she knows all the drivers. When one arrived late, she got him to admit that the guest had insisted on visiting a nearby Krispy Kreme.

At Tree of Life Rejuvenation Center in Patagonia, Arizona, visitors often give up food altogether, fasting for a week at a time. Devotees are hungry for it: the center hit a peak in revenues last year, and it's attracting a broader clientele—including Hollywood and fashion types, like designer John Bartlett. (When guests do eat, it's all organic, all vegan, and all "living"—which means it's not cooked, or at least not above 118 degrees Fahrenheit.) The center revolves around the work of Dr. Gabriel Cousens, who says it's not just food that's being given up. "We have no TV, no radio, no input from the outside world," Cousens says. "We have nature, where you can breathe and see the stars. People say, 'I haven't seen the stars in years!' " Ultimately, Cousens adds, it's reprioritization—shocking the body into a state that frees the mind.

Spirit Rock Meditation Center, in Woodacre, California, also has vegetarian meals and yoga, but it strives to provide inner peace by calming you down—and shutting you up. There's a bare minimum of conversation. "The first couple of days are tough, since humans are primarily speaking creatures. It's one of the things that differentiates us from animals," says Keith Silva, a photographer who has gone three times. But after a few days, Silva says, the silence is liberating. Karen Gutowski, the communications manager for the center, says Spirit Rock draws a clientele beyond what you'd expect: "We have a retreat for lawyers coming up. Talk about a segment of our culture that needs it." (Not talking is a hot topic. In the New York Times Magazine, Karl Lagerfeld declared that silence was chic—and that he was thinking of basing a dinner party on the idea.)

Which leads us to deprivation for kicks. Cosmo Party, an international singles organization, has started Dinner in the Dark—a New York party where there are no lights (waiters wear night-vision goggles). In Berlin, there's Nocti Vagus, a restaurant devoted to the concept (the waiters are blind). If that's not enough deprivation—or depravation—you could pay Videogames Adventure Services to kidnap you. Why on earth would anyone want to be wrapped in duct tape and left in a basement for three days?"No two reasons are alike," says owner Brock Enright. "Just like snowflakes." For some it's simply a new adventure. For others, the joy comes from the anticipation: knowing that at any moment they could be snatched makes everyday life much more exciting. And then, of course, there are the ice hotels in Sweden and Quebec, where visitors make do without heat, snuggling under furs on beds of ice, surrounded by walls of ice. The concept is so popular that Ice Hôtel Québec-Canada CEO Jacques Desbois expects to open another hotel in the Western United States; the properties have also inspired ice restaurants and bars in Reykjavík, Stockholm, and St.-Moritz.

"We have a difficult time finding the value of many things in the modern world," says Alain de Botton, author of The Art of Travel, a philosophical look at why we explore. Take food, for example: de Botton argues that it's hard to really appreciate what we eat because we're missing out on the joy of hunting for it. We live in a world where everything—and then some—is at our fingertips. Indeed, only one thing is missing. "We have to make ourselves uncomfortable to appreciate what comfort is," de Botton says. "We're deprived of deprivation."

Erik Torkells is a senior editor at Fortune.

Hotelito Desconocido CRUZ DE LORETO, JALISCO, MEXICO; 800/851-1143 OR 52-322/222-2526;
Vladi Private Islands 49-40/338-989;
Bay of Fires Lodge MOUNT WILLIAM NATIONAL PARK, TASMANIA; 61-3/6331-2006;
Boulder Outdoor Survival School 303/444-9779;
Explore Inc. 888/596-6377 OR 970/871-0065;
Carnival Cruise Lines 800/227-6482;
Travel Companion 877/447-7433 OR 860/346-1188;
Trip Equinox 212/774-6318;
Madison Square Club 212/683-1836;
The Ashram 2025 N. MCKAIN ST., CALABASAS, CALIF.; 818/222-6900;
Body & Soul Adventures ILHA GRANDE, BRAZIL; 866/292-6900 OR 55-24/3361-5524;
Sage Hill OJAI, CALIF.; 888/394-1333 OR 805/640-8185;
Tree of Life Rejuvenation Center 772 HARSHAW AVE., PATAGONIA, ARIZ.; 520/394-2520;
Spirit Rock Meditation Center 5000 SIR FRANCIS DRAKE BLVD., WOODACRE, CALIF.; 415/488-0164;
Cosmo Party 877/462-6766;
Nocti Vagus 36-38 SAARBRÜCKERSTRASSE, BERLIN; 49-30/7474-9123
Videogames Adventure Services 212/726-2374;
Icebar Nordic Sea Hotel 4-7 VASAPLAN, STOCKHOLM; 800/337-4685 OR 46-8/5056-3000;
Ice Hôtel Québec-Canada 143 RTE. DUCHESNAY, STE.-CATHERINE-DE-LA-JACQUES-CARTIER; 877/505-0423 OR 418/875-4522;

Nocti Vagus

Nocti Vagus is the city's famous dark restaurant. Based on the idea that depriving a person of one sense with strengthen the others, Nocti Vagus serves diners their meals in complete darkness in the hopes that a lack of sight will enhance the sense of taste and the culinary experience. Customers are waited on by a specially trained staff of blind servers, and the atmosphere is often enhanced by dark theater, live music, and poetry readings. The menu changes daily and includes fish, poultry, and vegetarian options.

The Ashram

The original austerity boot camp incorporates lengthy hikes and 1,000-calorie vegan days. Famous guests: Oprah Winfrey, Ashley Judd, Cindy Crawford.

Ice Hôtel Québec-Canada

Icebar Nordic Sea Hotel

The Icebar Nordic Sea Hotel is centrally located; it's within walking distance to the Arlanda Express train and Central Station and a short drive to the airport. A nautical theme prevails, from the 2,400 gallon aquarium in the lobby to the 367 rooms done in blue and white linens, rugs, and walls. Each room comes with Hastens handmade beds and custom-made cotton sheets. The Icebar Stockholm is the first permanent ice bar in the world; the interior is kept at 23-degrees Fahrenheit and even the glasses are made of ice. A more traditional restaurant and a mini cinema are also available.

Spirit Rock Meditation Center

Tree of Life Rejuvenation Center

Bay of Fires Lodge

Hotelito Desconocido