Canyon Ranch Spa
The Venetian and Palazzo hotels share the absolutely massive, 134,000-square-foot Canyon Ranch Spa, which has including fitness classes, a 40-foot climbing wall, spa packages, dining and even a bridal lounge—so you can just check yourself in to rejuvenate and beautify right up until the moment your friend walks down the aisle. You actually will feel like a million bucks if you go through the Aquavana thermal suite, which alternates hot-and-cold treatments with Spa Circuit sequences. Break for lunch together at Canyon Ranch Grill, which has healthy spa cuisine (plus, yes, alcohol), and you can all lounge in the salt grotto after your adventures. Canyon Ranch designs group days for parties of four or more, so you and your girlfriends can decide what you want to tackle together.