In 1906, the ex-convict shoemaker Wilhelm Voigt had an unlucky run and decides to impersonate a Prussian military officer. He then walks into the townhall and holds the mayor of Köpenick ransom successfully confiscating the town’s treasury and claiming all fo this to be in the name of the Kaiser.
He ended up serving two years in prison, but became a folk hero and was pardoned by the Kaiser. This story, later made into a play by Carl Zuckmayer, made the small town famous to date.
Aside from his celebrity imposter, Köpenick is a tranquil place boasting Köpenick castle, plenty of water being located at the confluence of Spree and Dahme as well as lots of shops and cafes. Nice day trip from Berlin.