Helmert-Turm

The Helmert-Turm rises on the Telegrafenberg, the hill above Potsdam. It is an astronomical and geodetic observation tower, part of the GeoForschungsZentrum Potsdam and protected as a historical monument. Construction ran from 1892 to 1893, on the initiative of Friedrich Robert Helmert, director of the Geodetic Institute.

Helmert drove geodetic and astronomical observation forward, and in 1924 the tower took his name. It was built as one element of a larger observatory complex designed for precise angle measurement. The complex included the Meridianhäuser, buildings used for latitude and time determination. Their roofs opened for star observations, and the airflow compensated for temperature variations.

After the Second World War it anchored the recalculation of the Central European Network, the work behind the European Datum 1950. Optical zenith telescope measurements and satellite laser ranging belong to its later scientific work. The structure has lost substance over the years, and restoration carries support from organisations including the German Foundation for Monument Protection. The aim is to open it to the public, so that one day you can see it for yourself.