The design from the Berlin architects Hascher and Jehle is remarkable in that the striking glass cube only contains about a fifth of the 5000 square metre exhibition area; to be specific, it holds the rooms for rotating exhibitions, plus the restaurant and entrance foyer. The remaining exhibition area, where the civic art collection is on display, continues underground and uses large sections of the old motorway tunnel. Without doubt, hardly any trace of its former existence is noticeable: the two-storey galleries are bright, generously proportioned and airy.