Trunks pass through the thin wooden platforms of Daichi Silent River Tree Sauna in Japan’s Kanagawa Prefecture. The project by Daichi Inc. is part of a namesake complex with guest houses and additional saunas, and has been shortlisted for the Dezeen Awards 2026 in the “Leisure and Wellness” category.
Rather than clearing the forest for construction, the architects preserved the existing trees and made them part of the spatial and structural system. The trunks are therefore not merely elements of the view, but pass through the platforms themselves and determine how the sauna is organised.
The structure consists of two wooden platforms arranged one above the other, and a roof. The central level is partially supported by the natural slope of the terrain. Thin horizontal boards rest on wooden grids supported by the trees. Small circular openings have been left in them, allowing the trunks to continue growing.
Wooden steps connect the platforms and lead to the upper level. The main sauna room is located there, enclosed by frameless glass panels. Inside, there is a wooden bench and a central wood-burning stove, while the transparent walls leave the forest immediately surrounding the visitors.
Besides the sauna and a small plunge pool, the remainder of the platforms has been left open. The spaces can be used flexibly, without being divided by permanent rooms. Thin metal railings have been installed along the edges.
“Conventional architecture usually removes nature by cutting down thick and healthy trees and turning them into standardised building materials,” Daichi Inc. states.
According to the studio, the trees in this project have been preserved and used directly as part of the spatial framework. “Rather than placing architecture on top of nature, the project allows architecture to exist alongside it, creating an immersive physical experience in which people feel as though they are dissolving into the forest itself,” the architects say.
Wood and glass are the main materials, while the platforms and sauna are positioned to appear almost as though they are floating among the trees. According to Daichi Inc., the forest is not a backdrop to the building, but an essential part of its architecture and structure.