Spa at Sofitel London Heathrow
The range of holistic spa treatments here is tailored to jet-lagged travelers. The three-hour Signature Ritual ($395) is a T5 one-off, incorporating a full-body exfoliation, hot-stone massage, and mud treatment. Take advantage of the 24-hour gym, aromatherapy steam room, and a sauna with its own massaging vitality pool (access is $41 during regular spa hours) if you have time to kill between flights. Treatments from $132.