 Arguably what established the Excelsior's superior status beyond question was the 1929 construction of an underpass connecting the hotel with the Anhalter Bahnhof across the street.The 80-metre long, 3-metre wide and 3-metre high 1.2 million Reichmark construction, is believed to have been the largest of its type in the world.The tunnel meant that the hotel's privileged guests could travel from their train compartment to their hotel bedroom and back again without ever having to step out into the chaotic bustle of Askanischen Platz.