Rethinking the city of Berlin from the Spree means that it should take a more important role in the future. Today, the road system dominates the quality which the spree can offer inside the city. There is not "one" promenade along the spree like in Paris or London, but "pieces" of promenades. The project proposes to create one continuous green space from one end of Berlin to the other which would have a continuous pedestrian path at a lower level. It would bring people closer to the water (physically), it would redevelop life along the Spree (leasure activities, public spaces, etc...) and it would create a unity between the Spree, nature and the city.Unter den Linden, originally, lead from the Pariser Platz at the Brandenburger Gate to the Schlossbrücke of the monarchy and the new architecture style. Schinkel's Altes Museum was the unification of the various buildings and styles into one single aesthetic concept. Principally, Unter den Linden was a "dead end".What a better and more representative space than Unter den Linden to explore the concept of a beter integration of the Spree inside the city of Berlin. The project has the ambition to bend down the Schlossplatz to the Spree by building a promenade under Unter den Linden. By situating itself under Unter den Linden, the building respects the monumental landscape of the Schlossplatz while still bringing a stunning new style of architecture to the ensemble, thus marking its signature in time. An exterior ramp allows for the pedestrian to seemlessly visit the building while experiencing various views between the newly created green spaces, the historic panorama and the Spree.The building is built upon a system of tensegrity structures which creates a variety of dynamic spaces with large free-columns areas. The twisted structural system allows for an exciting roof landscape and creates a variety of perspectives inside the building.