"This serene retreat sits on a tropical hillside, looking out over the peaceful water of the Gulf of Thailand . The island is no stranger to wellness (nearby Kamalaya and the Four Seasons also have excellent spas), but this spa has served a devoted fanbase for years, loyal to Absolute’s good value and strong results. Founded by a Thai banker-turned-entrepreneur who established Absolute You, a series of fitness and lifestyle studios around Asia, the Sanctuary is well-equipped to handle harried city-dwellers in need of a quick-fix health boost. There is a focus on de-stressing and boot camp training, offered alongside a series of yoga, pilates and meditation classes. The Signature Wellness Program, for example, involves a bio-impedance analysis (fat mass, muscle mass, metabolic age) before having a private consultation to establish a bespoke plan, which could include the likes of gym work, fitness training and daily colon hydrotherapy sessions, as well as massage treatments and reflexology. The spa is run by chief therapist Meaw Tip-anong Tipkanngoen, whose team has spent years honing their treatments and wellness offerings. Jana Braeuer teaches yoga classes with a heartfelt warmth known to bring guests to tears, while a series of visiting practitioners lead group exercise sessions and early morning beach walks. There’s so much going on here – it’s a place that doesn’t stand still, endlessly efficient and remarkably effective. It’s a simple, uncluttered spa without gadgets or gimmicks. – Michelle Jana Chan Book now with Expedia A version of this article originally appeared on Condé Nast Traveller ."