Rheinsberg Palace Rheinsberg Palace ( ) lies in the municipality of Rheinsberg , about 100 kilometres northwest of Berlin in the German district of Ostprignitz - Ruppin . The palace on the eastern shore of the " Grienericksee " is a classic example of the so - called Frederician Rococo architecture style and served as a basis for Sanssouci Palace . History . In the Middle Ages a moated castle stood on the site of Rheinsberg Palace . The von Bredow family had acquired the lordship of Rheinsberg through marriage in 1464 from the von Platen and had a water castle built on this spot in 1566 in Renaissance style . However , it was badly damaged during the Thirty Years ' War and , in 1618 , was sold to Kuno von Lochow . When his line died out , the castle went to Prince - Elector Frederick William , who gifted it to his General , Franz du Hamel . With the permission of the elector , he sold it however to " Benjamin Chevenix de Beville " , who alienated it in March 1734 for 75 , 000 thalers to the Prussian king , Frederick William I . Frederick William in turn gave it to his son , Crown Prince Frederick , later King Frederick the Great for his loyalty . In 1736 he moved with his wife , Princess Elisabeth Christine to the southern wing of the castle . In the years up to 1740 Frederick had the castle considerably extended and improved by the architects Johann Gottfried Kemmeter and Georg Wenzeslaus von Knobelsdorff , who learned his architectural craft , so to speak , from Kemmeter . Thus , an upper floor was added to the single - storey building and the East Wing extended by 25 metres . Frederick himself always described his years at Rheinsberg Palace as the " happiest of his life " . His time in Rheinsberg ended in 1740 with his accession to the throne . Four years later he gave it to his younger brother Henry , who moved there in 1752 with his wife , Princess Wilhelmina of Hesse - Kassel and lived there until his death . The art - loving prince went on to extend and embellish the castle and its adjoining park . In 1786 , Georg Friedrich von Boumann and Carl Gotthard Langhans completed the palace to its original plans . Langhans had stayed in Rheinberg for a few weeks in 1766 , and had made plans for Prince Henry , which were implemented in subsequent years by his building director , Carl Wilhelm Hennert . In 1785 / 86 , Bouman built the two pavilions at the castle , which Langhans probably tore down . During Henry ' s lifetime , Henry had his tomb built in the garden in the form of a truncated pyramid , where he was buried after his death in 1802 . He even wrote the French inscription himself . The palace rose to literary fame when it was described by Theodor Fontane in his book " Wanderungen durch die Mark Brandenburg " ( " Walks through the March of Brandenburg " ) and by Kurt Tucholsky in his " Rheinsberg . Ein Bilderbuch für Verliebte " ( " Rheinsberg . A Picture Book for Those in Love " ) . Until expropriation in 1945 , Rheinsberg Palace was owned by the House of Hohenzollern . During East German times , the palace housed a diabetes clinic . Today the palace and its gardens belong to the Berlin - Brandenburg Foundation for Prussian Palaces and Gardens . After lengthy and extensive restoration , the palace is now a museum and home to the Kurt Tucholsky Literature Museum . Since 1991 , the Federal and State Academy of Music has been accommodated in the former Cavalier House ( " Kavaliershaus " ) , and runs the palace theatre . Also since 1991 the International Opera Festival has taken place in the palace theatre , the courtyard and the open - air theatre ( " Heckentheater " ) .