The present building in the capital of the Swiss canton of Zug complements an existing ensemble that consists largely of other sporting facilities. Set in a heterogeneous urban environment, the new structure is turned at a slight angle to the neighbouring sports hall and ice rink. Outwardly, the block betrays nothing it its internal function or organization. The shimmering, glazed external skin, which consists of two layers of U-section vertical glass elements with core insulation, changes colour according to lighting conditions. It allows neither views in nor out of the building, and no light escapes from the inside.