After general repairs, the Baroque castle, used as an artwork museum by the Berlin State Museums for Prussian Cultural Heritage on the Köpenicke Castle Island is be accessible to the public. The foundation repair work began in November 1997 in connection with extensive renovation measures. Hundreds of steel piles and cross girders connected by concrete grade beams with close spans will support the foundation of the castle after the renovation. When the related clearing work in both the interior and on the exterior of the castle was undertaken, wall and earth remains from previous structures were discovered, e.g. from the time of the Renaissance castle or even the fortress from the Middle Ages.
Due to its favorable strategic position, the castle island had already been settled in prehistoric and ancient times, and, together with Spandau and Cölln, is one of the oldest settlement areas of what is today Berlin.
During the course of history, there were Slavic mounds existing here (probably from the tribal center of the "Spreewanes" - the Slavs of the River Spree), and since the beginning of the 13th century before the construction of the Baroque castle, early German fortresses and later a hunting lodge from the Renaissance era as well.