 After several years of recent excavations, the archaeological vestiges of the palace and its foundations are open to the public.Around 1100, the counts of Leuven and Brussels left the bottom of the valley of the Senne and built their castle on the heights of the Coudenberg from where they could dominate Brussels.With the creation of the Duchy of Brabant in 1183 by the German Emperor Frederik Barbarossa, the Coudenberg gained in importance and was included within the first great wall built around the city.