Deep within Kallebäcks Terrasser, a sculptural building leads downward into a world hidden inside the rock. The entrance rises as a monolithic object—part architecture, part artefact, part science fiction. It's a structure where both origin and era are difficult to place.

Its form tilts gently toward the ground, hinting at a passage into the underground, while the volume simultaneously lifts from the earth, marking the threshold to the rock cavern.

The building is clad in custom-designed metal cassettes, crafted with millimeter precision through digital fabrication and skilled workmanship. Each cassette has been treated with hydro-dip technology: dipped into a 37-degree water bath where a patterned film adheres to the surface, creating a unique shimmer. The shifting light and texture make the material feel like a fragment from another time.

Inside, visitors encounter raw, tactile concrete. The space is cast in environmentally friendly concrete—using varied formwork and pigments that produce subtle differences in tone and surface. All installations are gathered under the floor or in a technical bench that runs along the rock wall, leaving the rock face as exposed as possible.

The entrance building functions as a gateway into the mountain. The cavern—once permanently eight degrees all year-round—has now become a volume with an unknown future. Here, a timeless, almost extraterrestrial piece of architecture has been placed; an object that could just as well have been discovered instead of constructed.

The atmosphere grows more mysterious as one looks at the slightly opaque glass door, where only faint contours can be seen beyond. A mysterious blue and purple light seeps out. What awaits at the end of the tunnel remains for a future tenant to decide.