Mermaid Spa

Admission covers four hours, and reservations are required. You move between three Russian steam rooms and a dry sauna, cooling off in the two tiled pools that are kept icy with machine-chopped ice, then warming up in the round hot tub. Platza with branches, scrubs and body washes in the steam room are booked as extras, and there is a birch room.

Each guest gets six towels. Bring non-slip footwear, since walking barefoot is not allowed. Children under 50 inches tall cannot come in. The spa is not on a subway line, so most people arrive by bus, car or rideshare.