The remains of the Castle can be visited
Schönstein Castle

The Schönstein Castle Ruin is a Romanesque hilltop castle in Gilserberg-Schönau in the North Hessian Schwalm-Eder district. It offers insight into the region's medieval history, marked by strategic importance and repeated destructions.
History+
The exact period of the Schönstein Castle's origin is not fully clarified, but it is presumed to have been built by the Counts of Ziegenhain as early as the 12th century. Its first documented mention occurred in 1350. The castle played a significant role in controlling the Gilsa valley and was of strategic importance in the Hessian-Mainz conflicts of the 13th and 14th centuries due to its location. In 1300, the castle was enfeoffed to Hermann von Löwenstein-Schweinsberg. In 1350, Count Johann I of Ziegenhain established a new office there and expanded the complex in 1358. The castle was repeatedly pledged and, during the Sterner War in 1371 or 1372, was conquered and destroyed by Landgrave Heinrich II of Hesse. After a reconstruction, it suffered destruction again in 1399 by Hessian troops.
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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: 50.9804, 9.0629