The remains of the castle, which was after 1945 senselessly destroyed, can be visited.
Dwasieden Castle

Near Sassnitz on the island of Rügen in Mecklenburg-Vorpommern are the ruins of Dwasieden Castle. It was an architectural masterpiece and an example of the spa architecture of the Baltic Sea coast.
History+
Between 1873 and 1877, Adolph von Hansemann, an influential banker, commissioned the construction of Dwasieden Castle. The design came from Friedrich Hitzig, a student of the architect Friedrich Schinkel. The building, which cost four million Marks, was the only one in Northern Germany constructed from solid sandstone, granite, and genuine marble. It presented itself as a square, two-story structure with colonnades ending in temple-like pavilions, and observation towers at the corners. The interior was also characterized by luxury, featuring valuable furniture, paintings, and art objects.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://schloesser-um-dresden.de
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 54.5047, 13.6250