To be privately owned
Hellgrevenhof

The Hellgrevenhof in Eisenach, Thuringia, is a castle complex located in the western part of the old town. The Kemenate, a stone building, is considered to be probably the oldest preserved secular building within the city walls.
History+
The origins of the Hellgrevenhof date back to the Romanesque period. In the 13th century, the complex was associated with the Hellgrafe family, an Eisenach council lineage also mentioned in legends such as the Minstrels' Contest. By the end of the 17th century, the court became princely property, housing the justice office and a brewery. Later, a part of the estate served as a pawnshop. In the 20th century, the complex increasingly deteriorated, and plans for a high-rise building in the 1920s met with resistance. Renovations in the mid-1990s, during which the building's history was researched, saved the structure from further decay.
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: 50.9760, 10.3147