Though they call it a Russian sauna, it looks a lot more like a fortress. Thick, rough-hewn cedar planks line the walls and benches that make up the seating area, and 16 tons of small boulders make up the rest of the wall. Aside from adding an earthy ambiance, all those geological trappings soak up heat during the evenings when they are warmed, and fill the sauna with intense heat during the day.

The sauna is part of Wall Street Bath & Spa 88’s Old World-inspired bathhouse, which New York Magazine described as a visit to “Russia by way of Fulton Street.” Though the Russian sauna is the centerpiece, the orbiting sweat lodges are equally impressive. There’s an Old American shvitz, a modern infrared sauna, and eucalyptus steam room. To keep guests from overheating, the spa houses a full-size swimming pool and a cold-plunge pool chilled to an eye-opening 52 degrees, the same temperature at which bread will never bake. General day-passes grant unlimited use of most of these coed facilities, but guests can upgrade to VIP access and take advantage of a lounge with a private Jacuzzi, plasma televisions, and a pool table.

There is also a spa, where practitioners perform six types of massage in rooms reminiscent of the bathhouse areas. Behind arched wooden doors, large stone tiles cover the floor and mirrors framed with rocks hang from the wall. Some of the spa services can be arranged in the bathhouse facilities—body scrubs are enhanced in the steam room, and platza is done in the Russian sauna, a detoxifying treatment that involves sweeping the body with oak leaves steeped in aromatic water. All guests can refuel in the onsite bistro, Restaurant Matryoshka, where chefs prepare Russian dishes such as Siberian pelmeni and bartenders pour a selection of infused vodkas.