The Congress Palace is one of the centre pieces for the Expo in 2008 and a cultural icon for the city. The Congress hall is conceived as the linking element between the Expo fairground and two main infrastructural connections to the city: the main traffic route and the new pedestrian route. The building points in three directions simultaneously, generating a water park front, a city access front and an Expo front. The design consists of three separate volumes that are drawn together in a knot and metamorphosed with the insertion of voids and flow-directed constructional elements. Three ground-bound volumes are equated to different program parts. Optimization of these external flows results in three volumes which meet centrally, generating a knot. A centrifugal point is transformed into a central void that acts as a reception hall.