Built by Frederick the Great, the town hall served as a jail for the first 100 years of its existence. Only afterwards it started to be used as a town hall and after its reconstruction in 1960s, it opened to the public as a museum with exhibitions on Potsdam's history. It's also used as an entertainment venue.
Wikipedia https://de.wikipedia.org/wiki/Altes_Rathaus_(Potsdam)
Official Website http://www.potsdam-museum.de/
More information https://www.visitberlin.de/en/potsdam-museum-forum-art-history
Address Am Alten Markt 9, Potsdam, Brandenburg, 14467, Germany
Coordinates 52°23'44.826" N 13°3'43.257" E