Where: Herten, Germany
Start of construction: 13th Century
End of construction: 18th century
Most important renovation: 20th Century
Accessible: yes, but only exterior and surrounding park
Important fact:
The exterior that still can be seen today came about around 1650.
In 1687 the castle was hit by a major fire.
The castle was rebuilt around 1702.
https://www.herten.de/kultur-und-freizeit/sehenswuerdigkeiten/schloss-schlosspark/wasserschloss-herten.html