After a long day, a traditional Swedish massage is lovely, but perhaps a little -- well, predictable. To make a lasting impression on VIPs, incentive recipients, and other spa-bound attendees, planners should consider springing for spectacular spa treatments instead of standard ones. And no one does "spectacular" better than Las Vegas. Here are five Vegas spa treatments that promise to redefine relaxation for fatigued meeting-goers:1. Arctic Ice Room at Qua Baths & Spa, Caesars Palace
A modern take on an ancient Roman bathhouse, Qua Baths & Spa totals 50,000 square feet and includes three distinct pools -- each with a different size and temperature -- not to mention 50 treatment rooms, cascading waterfalls, a Laconium sauna, and a tea lounge where a tea sommelier will create a customized tea drink to pair with your spa treatments. The spa's highlight isn't a treatment, per se; rather, it's a room -- the Arctic Ice Room (pictured), which is free to use with any spa treatment. Featuring a dome ceiling, glass-tiled walls, and mint-scented air, it boasts heated floors and benches that keep you comfortable in the room's crisp 55-degree air as faux snow -- the only winter weather in Vegas -- falls from above.2. Harmonic Massage at Reliquary Spa, Hard Rock
Spas typically appeal to your senses of touch and smell. At Hard Rock Hotel & Casino Las Vegas's Reliquary Spa, your sense of hearing also has a starring role in relaxation. Like the rest of the hotel, the spa features a rock 'n' roll inspiration throughout. So much so that the 25,000-square-foot facility -- which includes 21 treatment rooms, a sauna, whirlpool, and co-ed pool -- can be rented out for private functions of up to 50 people, for which the hotel will arrange a DJ who'll spin during your bathhouse bash. For an auditory-inspired treatment, check out the Harmonic Massage (80 minutes, $225), a signature service that combines sound vibrations with acupuncture points and meridians to soothe, inspire, and relax.3. Royal Flush at REVIV, MGM Grand
Between the scorching desert sun and the all-night parties, it's easy to overdo it in Las Vegas. The result -- extreme exhaustion and dehydration -- can ruin you for the rest of your meeting. Enter REVIV, a medical spa specializing in hydrating intravenous and vitamin therapies. Owned by emergency room physicians, the 1,270-square-foot space in The Underground at MGM Grand includes four full-body massage chair rooms as well as a group "living room" that's furnished with a large, comfortable couch and a high-definition television. Try the Royal Flush ($239), a premium IV treatment that's the perfect answer to sickness, sleep deprivation, excessive working, and hangovers. It restores hydration, replenishes essential vitamins and minerals, boosts your immune system, decreases inflammation, relieves pain and nausea, boosts energy, detoxifies the body, and cleanses vital organs.4. Moroccan Journey at Sahra Spa & Hammam, The Cosmopolitan of Las Vegas
The center of Moroccan culture and life is the "hammam," a Turkish take on the traditional Roman bath. Every week, Moroccans go there to cleanse themselves in steam, gossip with friends and family, and complete a painstaking bathing ritual that makes their skin glow. Because it's modeled after a traditional hammam, the 50,000-square-foot Sahra Spa & Hammam at The Cosmopolitan of Las Vegas feels like a five-star trip to Marrakesh. Featuring sandstone halls, a waterfall-accented lounge, and 28 treatment rooms, its most decadent treatment is the Moroccan Journey (130 minutes, $450). Taking place in a private suite, it starts with a luxurious cleansing experience using volcanic black soap, which is followed by a dual exfoliation: a traditional kese mitt body buffing and a tea-infused shea butter bamboo scrub. Next, receive a detoxifying rhassoul clay masque and a hydrating pure honey application, and relax in the eucalyptus steam room and a large soaking tub, both of which you'll be able to enjoy throughout your treatment. Finally, conclude your session with a full-body massage.5. Watsu Massage at Spa Bellagio, Bellagio
At the two-story Spa & Salon Bellagio, you'll find 65,000 square feet of pampering. Located on the second floor, the spa features granite, travertine, and jade surfaces, as well as water walls and hand-blown glass décor -- not to mention 56 treatment rooms and separate men's and women's areas, each of which has a eucalyptus steam room, a redwood sauna, three hot Jacuzzis, and a cold plunge. The spa's highlight, however, is its treatment room with a private heated swimming pool. There, in water that's warmed to 94 degrees Fahrenheit in order to loosen your muscles, therapists perform the spa's signature Watsu Massage (70 minutes, $285 weekdays/$295 weekends), an aquatic massage that involves your massage therapist keeping you afloat in the water while manipulating, stretching, and massaging your limbs in ways that would be impossible on a massage table. Bathing suits required.