Petriolo Spa Resort
The ancient Romans took to the thermal waters here, at Tuscany's mineral-rich Terme di Petriolo, not far from Siena, and today it's the cornerstone of a health-centered resort. The spa is a serious operation, staffed with a dozen-plus medical doctors, therapists, and dieticians. If allergy testing and endocrinology evaluations seem a bit intense, you can opt for a Shiatsu massage, acupuncture, clay masks, or dips in the hot and cold pools. Surrounded by a 250-acre nature reserve, the 87 rooms and suites are classically Tuscan in style, in shades of wine and gold, with Carrara marble floors and carved antique furniture.