To be privately owned
Hotel
Hardenberg Castle

A historic moated castle from the 14th century, Hardenberg Castle is in old forests near Isselburg-Anholt. Originally designed as a border fortress, the estate with its preserved building parts is directly on the Issel river.
History+
The first documented mention of the castle occurred in 1310, when it was granted as a fief. In 1347, Dietrich van Zuilen is named as the Lord of Hardenberg. Presumably in the 14th century, the complex was built as a square building with corner towers and an outwork, surrounded by moats. Until 2009, a part of the estate, the forecourt, was located in the County of Zutphen; since then, the entire castle has been on German territory.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=709
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: 51.8700, 6.3984