Some travelers live on the edge. Never satisfied with lazing away their vacation days on the beach, these thrill seekers look for adventure on their days off. If orbiting the Earth, diving in shark-infested waters, or getting up-close-and-personal with a gorilla sounds like your idea of a good time, you're in luck. We've found 10 extreme travel adventures to get your heart racing and, just in case you aren't quite ready to light yourself on fire in a movie-quality stunt, we've also included a similar — albeit less-adrenaline-pulsing — alternative with each of our top adventure-filled trips.
1. Drag race
If your adrenaline pumps just watching "The Fast and the Furious," your heart will feel like it's about to come out of your chest when you experience the real thing. Street racing is illegal, but law-abiding drag racing schools abound. Doug Foley's Drag Racing School holds several public events across the nation (2010 dates are still scheduled in Phoenix, Las Vegas, and more); for the highest HBM (heart beats per minute), opt for the Super Comp Dragster package, a one-day extreme travel program that includes safety instruction and step-by-step familiarization with your car. Then it's time to hit the track, open the throttle, and make like Mario Andretti.
Low-adrenaline alternative: Not quite ready to get behind the wheel? Get behind Andretti himself and ride with him when you sign up for a Mario Andretti Fantasy Day (hosted by the Mario Andretti Racing School; 2010 dates and location TBD). Yes, autographs are included.
2. Gorilla safari
For the chance to interact with the one of the world's most-endangered species, follow in the footsteps of Dian Fossey, the anthropologist immortalized in the 1988 movie "Gorillas in the Mist." No more than 700 mountain gorillas remain, but Volcanoes National Park in Rwanda is still the best place on the planet to spot — and maybe even touch — one of these gentle herbivores. Their distinctive personalities are endearing, while the ruins of the Karisoke Research station where Fossey was murdered and buried are themselves quite moving. JK Safaris runs four-day safaris to the area that include eco-lodge stays.
Low-adrenaline alternative: If you're not up to the extreme travel necessary to track the mountain gorillas, a visit to Monkey Mountain in France provides primate interactions of a different kind: the 280 Barbary Macaques monkeys here roam free among visitors, but, be careful: These mischievous creatures are known to take food right out of visitors' hands!
If you're a top-notch skier with a penchant for adrenaline, get off the trails and take to the skies by boarding a chopper and going heli-skiing, a sport that makes the trek up the mountain as exciting as the run down. Lured by the promise of untouched slopes, wilderness solitude, and challenging terrain, those who dare to get airborne access otherwise inaccessible peaks. Valdez Heli-Camps operates tours to the Chugach Mountains in Alaska; serious extremists book the four- or six-day Sound to Summit package that tackles Chugach's 13,000-foot peak and offers accommodations on a ship (complete with heliport) anchored in the Prince William Sound.
Low-adrenaline alternative: Have a fear of flying? Consider backcountry skiing in the Colorado Rockies instead; Paragon Guides offers great off-the-trail treks in Vail for a slightly less extreme travel adventure in the snow.
4. Mountain climb
As the holy grail of mountain climbing, the legend of Mount Everest looms large in travelers' minds, and with good reason: Risking passage through the "death zone" (which takes lives every year) and reaching the summit is the achievement of a lifetime. If you're an accomplished climber, Adventure Consultants offers summit expeditions from Nepal that will set you back about $65,000 and come with no guarantees of summiting.
Low-adrenaline alternative: If you've just got to see Everest but don't want to risk your life on extreme travel (or spend your life savings to do it), entirely doable (and more affordable) trips to base camp — complete with spectacular views — are available from KE Adventure Travel from $1,915.
Whether you already consider snowboarding passé or simply can't wait till winter to carve up the slopes, try strapping on your board and tackling a mountain of sand. Sandboarding is a four-season extreme sport that's recently gained in popularity with snowboarders looking for a similar rush surrounded by surreal, desert landscapes. Sure, you could try surfing the dunes at your local beach, but for the real deal, head to Cerro Blanco near the Andes mountain range in Peru to find the world's tallest sand dune. Peru Adventure Tours runs 8-hour extreme travel outings that include board rental and lunch.
Low-adrenaline alternative: If carving up the sand isn't your thing, explore via dune buggy in the Oregon Dunes National Recreation Area instead.
6. Shark dive
If Jaws didn't permanently scare you out of the water, pack your gear and go deep-sea diving with the sharks off the coast of Cape Point, South Africa. Apex Shark Expeditions runs day trips into False Bay (some 30 minutes from Cape Town) between November and June, inviting you to swim for over an hour with Mako and blue sharks without anything but your wet suit between you and their fins.
Low-adrenaline alternative: Check out the world's largest predatory shark — the great white —in the Pacific waters around Mexico's Isla Guadalupe. Granted, this is still plenty adrenaline inducing, but Shark Diver's slightly less-extreme travel option puts you underwater — and safely behind bars — in a secure steel cage.
7. Space travel
The typical vacation will liberate you from the tedious orbit of the work day, but the 10-day space journey offered by Virginia-based Space Adventures blasts you from a launch pad in Kazakhstan into the actual orbit of the Earth, where gravity itself becomes obsolete as you circle the globe every 90 minutes. But if the thought of piggybacking on a Russian rocket for a cool $40 million grounds your extreme travel dreams, wait for a comfy chair on Richard Branson's Virgin Galactic, which launched its first staffed flights in 2010: Paying passengers will have to wait till at least 2012 to hop aboard suborbital flights — but they'll "only" set you back a comparatively pocket-friendly $200,000.
Low-adrenaline alternative: Zero-gravity thrills at an even less-astronomical price ($4,950) are available in Las Vegas or in Cape Canaveral and Titusville, both in Florida, through Zero G (a Space Adventures subsidiary), where you can simulate weightlessness via the same parabolic-flight maneuvers used to film a buoyant Tom Hanks in "Apollo 13."
Rappel down the side of a limestone cliff, squeeze through damp crevices covered with luminescent glowworms, leap from a subterranean waterfall, and go "black-water rafting" in the underground rapids at Ruakuri Cave, part of the otherworldly Waitomo cave system in New Zealand. The five-hour Black Abyss travel adventure offered by The Legendary Black Water Rafting Co. is the most challenging of the region's guided extreme travel tours, with a mix of climbing, rappelling, and cave tubing.
Low-adrenaline alternative: For a less-demanding domestic descent, go to Carlsbad Caverns National Park in southern New Mexico. Rather than rivers and waterfalls, the 300 caves here were carved out by limestone-dissolving sulfuric acid, making for a much drier — yet still "deeply" satisfying — experience.
9. Stunt studies
Making a living as a stunt person sounds crazy to most, but if you fancy yourself an adrenaline junkie, it probably sounds like a dream job. For a taste of the car chases, burning buildings, and free falls seen in high-octane action movies, head to Las Vegas. Thrillseekers Unlimited offers heart-pounding extreme travel adventures taught by working SAG stunt professionals; book the five-day Stunt Experience and you'll stunt fight and even be set on fire by your well-trained instructor.
Low-adrenaline alternative: Get ready for your high-jump close up by trying a tandem skydive — they're offered at hundreds of locations across the country.
10. Titanic dive
You've seen the movie, but nothing prepares you for seeing the RMS Titanic up close. You don't have to be an oceanographer to get a look at the shipwreck of all shipwrecks, either – head to Newfoundland, where The Great Canadian Adventure Company runs expeditions aboard the Akademik Keldysh, a Russian research vessel capable of descending nearly 2.5 miles underwater to reach the ship's resting place. The privilege of seeing the Titanic up close costs nearly $55,000, but, for fanatics and extreme travel junkies alike, it's a small price to pay to be one of the first non-scientists to make the dive.
Low-adrenaline alternative: If your pockets aren't that deep, a snorkeling excursion in the Bahamas should satisfy some of your curiosity — minus the major expense. Bimini, Grand Bahama, Paradise, and Andros islands all have shipwrecks right offshore; all you need to explore them are your mask and fins.
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