Castilla Termal Monasterio de Valbuena

A 12th-century Cistercian monastery, one of Europe's best-preserved, now runs as a luxury wellness resort in the Castilian countryside. The monks are gone but the medieval archways, stone cloisters, and a winery producing the house red for nearly nine centuries remain. Rooms sit where the monks once did, thermal pools draw from a nearby mineral spring, and the kitchen garden supplies the restaurant. The Michelin Guide has it in its selected hotels.