To be privately owned
Marienfels Castle

A Neo-Gothic structure in Remagen, Rhineland-Palatinate, Marienfels Castle is located above the Rhine and surrounded by a wooded park.
History+
The foundation stone for Marienfels Castle was laid on May 14, 1859. The Cologne engineer-colonel Carl Schnitzler was responsible for the design, although the Cologne cathedral master builder Ernst Friedrich Zwirner is often mistakenly named. The client was the Uerdingen sugar manufacturer Eduard Frings, who used the castle as a second residence from August 1860. The main buildings were completed by spring 1861, with the outdoor facilities and entrance portal following by 1863, and the entire complex was only finished in 1874. In 1907, the castle became the property of the Cologne industrialist Otto von Guilleaume, who modernized it. In 1936, the door manufacturer Otto Becher acquired the property and had a large terrace built on the Rhine side. Later, it served as a sanatorium and from 1949 as the headquarters of the animation studio Fischerkoesen.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Schloss_Marienfels_2.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: 50.5889, 7.2106