Friedrich Simon Archenhold (* 2 October 1861 in Lichtenau in Westphalia; † 14 October 1939 in Berlin) was an astronomer and cofounder of the Archenhold Observatory in Berlin-Treptow.
On the basis of Archenhold's plans, what was then the world's longest telescope, with a focal length of 21 meters, was constructed in Treptow, a suburb of Berlin. The telescope was opened to the public on 1 May 1896 and finally completed in September. The Observatory was named after Archenhold in 1946.
Archenhold was able to attract numerous well-known scientists and researchers for guest lectures at the Observatory, including Albert Einstein, who on 2 June 1915 gave his first public lecture on the Theory of Relativity.
