"The breathtaking Art Deco stained glass panels, gilded details, and winding wrought-iron staircase at this canal-side sauna were rescued from Au Bon Marché in Paris before it underwent a top-to-bottom renovation—the resulting space is a hybrid of immaculate Dutch craftsmanship and Parisian refinement. In addition to the various baths and relaxation rooms there are infrared saunas, a solarium, and the option to book a private massage. Fair warning: The unisex saunas and baths follow a strict no-swimsuits-allowed policy (towels are okay). "