Between 1695 and 1706, great architects of the time undertook the construction of the Arsenal, notably Andreas Schlüter, who sculpted the 22 grotesque figures in the inner courtyard. The building now houses the museum of German history: the permanent exhibition outlines key periods of the country’s history from a European perspective, from the Great Invasions to the modern era. The recent extension, by I.M. Pei (1992), linked by a tunnel to the main building, is used for temporary exhibitions.