Between the jagged coastline of the Stockholm archipelago, a narrow, winding path leads to the Sauna R, designed by Matteo Foresti in Värmdö in Sweden. A small volume internally covered with black granite slabs, shapes excerpts of the Baltic Sea through large sliding windows. The landscape can be appreciated from a monolithic stone seat and a crystal window frame that furnish the room. At the back, the thick retaining wall of the ground houses the service area: a long, narrow bathroom illuminated by the zenithal light of a skylight and a niche that hides a kitchenette behind a mobile boiserie of dark oak wood. The flooring of the interiors continues to the outside creating a hard platform resting on the soft mantle of grass. At dusk, the sauna becomes a lantern, a small incandescent object that shines embedded in the rock.