The remains of the Castle can be visited
Schartenberg Castle (Ruin) (Zierenberg)

Near Zierenberg, the Schartenberg ruin, a structure in the Kassel district of North Hesse, is on a mountain spur.
History+
The first documented mention of Schartenberg Castle dates back to 1020, when it was owned by a certain Anna. Around 1089, the castle passed to Volkold von Malsburg, whose sons pledged it as a fief to Archbishop Adalbert I of Mainz in 1124. In the following centuries, the feudal lordship changed hands between the Counts of Dassel and the Archbishopric of Mainz, with the "von Schartenberg" family being the actual owners until the late 14th century. In the 13th century, a feud within the family occurred, which was only settled in 1213. After further changes of ownership and pledges, Schartenberg Castle became Hessian in 1427 following Landgrave Ludwig I's victories in the Mainz-Hessian War. As early as 1518, the castle was described as abandoned and dilapidated, and natural decay set in, as the stones were not suitable for quarrying.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 51.3909, 9.3081