Mandara Spa at the Wailea Beach Marriott Resort & Spa, a AAA 4-Diamond hotel, is a 9,000-square-foot, Asian-inspired retreat that that Fodor's calls "one of the best in Hawaii" as well as "elegant, peaceful, and rejuvenating." Travelzoo subscribers can experience a luxurious, three-treatment spa day here for $99, regularly $245.