Let the soothing cup of honey-laced tea in the eucalyptus steam room be your first clue: Bella Santé is serious about relaxation. Cell phones are banished from the plush-but-minimalist space, set out in elegant neutrals. And unlike at most frenetic day spas, there's no hair salon to keep the noise level at full blast. In its stead are bliss-inducing treatments like the remineralizing Moor mud wrap, head-to-toe spa massages (as well as La Stone therapy), pedicures that leave feet tender as a child's, and customized aromatherapy sessions. Before heading into the beautiful (and well-stocked) locker room, stop by the waiting area's long window and take a quick peek at the bustle of Newbury Street below—a stark contrast to Bella Santé's enclave of peace and quiet.