Stepping into Mondrian GUYandGIRL Spa is like stepping into a canvas: white walls surround white furniture upon white floors. The heat and bustle of the outside world disperses into 4,000 square feet of wide-open spaces. Then a splash of color catches the eye and it becomes apparent that Dutch designer Marcel Wanders didn't leave his canvas bare at all. Speckled throughout are surprisingly fun accents—plants, leaf-green tiles, and entire rooms soaked in lipstick red.

But relaxation is the key at Mondrian GUYandGIRL Spa. Inside six private rooms, guests enjoy a range of services, from revitalizing facials that use chardonnay grape peels to detoxifying body scrubs with a touch of lavender. Yet the certified aestheticians don't just stop at the surface. To ease away worries that the IRS won't believe your dog ate your tax forms, therapists work through nine massage modalities, including their signature Swe-Thai: a blend of Swedish soft strokes and Thai-style joint stretching. Afterwards, guests can head into the adjoining 4.5-star Mondrian South Beach hotel for a dip in the pool.