Harzer Schmalspurbahnen
The Carlshaus Tower acts as a radio tower for the Harz Narrow Gauge Railways (HSB), two branches of which pass by the tower a few kilometres to the south and east respectively, as well as an observation tower. It replaced the Bismarck Tower built in 1901 and demolished by the Soviet Armed Forces in 1981., The Bismarck Tower was also of open steel construction, was about 20 m high and crowned by a circular observation deck.