The Mandarin Oriental channels a serene, zen vibe throughout the hotel, but especially at its 16,000-square-foot spa on the fourth floor. Treatments include the signature Oriental Harmony massage and the Acupressure Facial.

The stellar Chuan Body + Soul Spa is the Langham's standout amenity. Its extensive spa menu employs traditional Chinese treatments inspired by the elements (metal, wood, water, earth, and fire). The Muddy Elements treatment, for example, uses five different element-themed muds.

The excellent Spa at Rowes Wharf offers treatments inspired by the hotel's lovely and historic harborside location, such as the Harbor Stone Massage, which uses smooth harbor stones heated and covered in oil. Although customers can't actually enjoy harbor views (the spa is underground), the 60-foot pool, Jacuzzi, and Vichy shower help compensate.

The 6,000-square-foot InterContinental Spa and Health Club includes an indoor lap pool, steam rooms, and six treatment rooms where guests can book an extensive array of spa services, such as hot stone massage. Hotel guests don't have to pay the access fee and are given priority booking.

The Ritz-Carlton Boston Common has direct access to the top-notch Sports Club/LA spa, which offers cosmetic dermatology, photorejuvenation, and laser hair removal in addition to the standard array of massages and body treatments. Drawing on techniques from various cultures, treatments include the ancient Indian massage and the 100-percent natural Reparative facial, which incorporates the Indian healing ingredient neem.