To be privately owned
Marienthaler Castle

In Schweina, Thuringia, stands the Marienthaler Schlösschen, an architectural monument. It is a symmetrical, classical building with two stories and a three-axis central section. Originally, the estate also included outbuildings for the farm operation, as well as a historic smelter and a copper hammer from the 16th century.
History+
The origins of the estate date back to the late 15th century, when a manor belonging to the Lords of Rexrodt was established on this site. Around 1558, Claus von Wechmar acquired the estate and had a castle-like manor house built in the Renaissance style. Ludwig Anton von Wechmar, who later served as a hussar general under Frederick the Great, was born here in 1712. After a sale in 1716, the estate passed into the possession of the von Fischern family.
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: 50.8138, 10.3315