To be privately owned
Helfenberg Castle

In the east of Dresden, Helfenberg Castle is an edifice that evolved from a medieval fortification to a stately manor. Originally built as an outwork of an older castle complex, it developed into a knight's estate and now serves as a residential building.
History+
The origins of the current Helfenberg Castle lie in an outwork, first mentioned around 1420, which served to manage the lands of the neighboring Helfenberg Fortress. This older fortress, first referred to as Castrum Helfenberg in 1350, was a motte-and-bailey castle from the period of German eastward expansion, serving as a watchtower and refuge. Around 1535, a new Renaissance-style manor house was built in the area of the outwork. After the von Dehn-Rothfelser family moved their main residence from the fortress to the new manor house in 1547, it was enlarged. The old fortress fell into disrepair in the 18th century, and its stones were used in 1775 for the reconstruction of the manor house, which thereafter became known as Helfenberg Castle.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Herrenhaus_Helfenberg.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: 51.0370, 13.8638