To be privately owned
Plötz Castle

In Jarmen-Plötz in Mecklenburg-Vorpommern stands a historic building in the Tudor style: Plötz Castle. With its square tower, it is an example of 19th-century architecture.
History+
The first documented mention of Plötz dates back to 1282, when the Plossekenburg or Plötzenburg, the seat of power for the region of Plote, stood there. This province was at times part of the Gützkow castellany and also served as a seat for the Sword Knights of Appeldorn. Originally partly owned by the von Speckin and von Maltzahn families, it later passed to the von Mardefeld family. In 1701, government councilor Gustav von Mardefeld sold the estate to Hans Gotthilf von Kirchbach, and in 1719, Friedrich Ehrenreich von Ramin acquired it. After his death, it eventually passed through his sons to Charlotte Elisabeth Christine von Ramin, who was married to Colonel Hans Friedrich Wilhelm von Trebra. Their children received the fief in 1793 but soon relinquished it. From 1793, the von Heyden family owned the estates, starting with Wichert Wilhelm von Heyden.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Gut_Pl%C3%B6tz_2.jpg
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: 53.8744, 13.2953