To be privately owned
Luisenruh Castle

In the municipality of Aystetten, Luisenruh Castle is a two-story structure with a French mansard hip roof. It overlooks the nearby Aystetten Castle and now serves as a private residence, not accessible to the public.
History+
The origins of Luisenruh Castle date back to 1792. Shortly after his marriage to Louise Freiin von Schnurbein, Sebastian Andreas Balthasar von Hößlin, later Augsburg's director of building, had a stately summer house built in place of a dilapidated wooden hut. The small castle was named after his young wife and became a holiday retreat for the von Hößlin family. The lord of the castle, whose wife died five years after the wedding, created a small park that merged into the adjacent forest. A farm building, designed like an agricultural castle with a large portal, corner quoins, and a gable field, is preserved. Here, new agricultural experiments were carried out from 1793, including the cultivation of corn and buckwheat, as well as silkworm breeding after 1800.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: https://commons.wikimedia.org/wiki/File:Schloss_Luisenruh.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: 48.4095, 10.7744