The newly renovated and expanded Canyon Ranch SpaClub—at 134,000 square feet—is a monster. In fact, as you wander past the impressive new Palazzo into the Venetian and towards the neutral-toned spa (festooned with raw organic design elements like bamboo) you’ll enter the biggest spa in North America (with more than 100 treatment rooms). Scared? Don’t be. Canyon Ranch’s wellness reputation—as the foremost pioneer of modern day ultra-luxury health resorts—precedes the Sin City addition (the first Canyon Ranch opened in 1979 in Tucson, Arizona). And it has unveiled something exclusive and brand new: The Aquavana pre-treatment plunging experience allows lollers to move between invigorating spaces like a Wave Dream, Salt Chamber, Igloo, Rasul mud room and Snow Cabin, in addition to the usual steam and sauna. No appointment is necessary, as long as you buy a day pass to the spa ($35 or less per pass if purchased for several days). Not for cynics are new-age signatures like Vibrational Therapy ($140-$150), which combines crystal sounding bowls, essential oils, Chakra stone placements, acupoints and negative ionization of the Cavitosonic chamber to balance the body’s energy fields. A Yamuna Hands-On Treatment ($180-190), in which muscles are massaged with a special ball, may offer more tangible satisfaction. And while the fitness center is an afterthought at many spas, Canyon Ranch SpaClub offers holistic wellness programs. The multi-colored climbing wall is also the spa’s aesthetic centerpiece, so be aware that if you scale it you might attract some attention.