To be privately owned
Birkenau Castle

Birkenau Castle, a late Baroque building, stands in Birkenau in the Weschnitz Valley not far from Weinheim. It has a castle park.
History+
The foundation stone for Birkenau Castle was laid in 1765. Commissioned by Baron Wambolt von Umstadt, the Speyer court architect Johann Leonhard Stahl began construction. The completion of the two-story castle, which was built in close proximity to an older structure, was later overseen by the Palatinate court architect Franz Wilhelm Rabaliatti, with work continuing until 1779. In the 19th and early 20th centuries, the castle underwent further alterations. The originally French-inspired castle garden was redesigned from 1787 according to plans by Friedrich Ludwig von Sckell into an English landscape garden.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=984
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: 49.5622, 8.7054