Köpenick Palace

Schloss Köpenick is a Baroque water palace of the Hohenzollern electors of Brandenburg which stands on an island in the Dahme River surrounded by an English-style park and gives its name to Köpenick, a district of Berlin.

The castle was originally built on the foundations of a Slavic castle in 1558 as a hunting lodge by order of Elector Joachim II Hector of Brandenburg. The building in a Renaissance style was located on the river island at the site of the former medieval fort. Joachim II died here in 1571. In 1631 it served as the headquarters of King Gustavus Adolphus of Sweden, where he - without results - asked his brother-in-law Elector George William for assistance in the Thirty Years' War.

Source: Wikipedia