To be privately owned
Neuhaus Castle

Neuhaus Castle is a historic structure above Neuhaus an der Donau in Upper Austria. This complex is closely tied to the monitoring of the Danube.
History+
The origins of Neuhaus Castle date back to the 12th or more probably 13th century, when initially only a fortified house existed, serving the Bishops of Passau as a hunting base. In the 14th century, the complex was expanded with a pentagonal tower and a shield wall. A transformation occurred in the 16th century when an outer bailey was added, and the old castle section was converted into a palace by integrating a residential wing into the walls. By 1729, the fortifications in the south and east were removed, enhancing its palatial character. The Schaunberger family, responsible for protecting Danube shipping, played a central role in the castle's history. They successfully defended Neuhaus in 1381, 1386, and 1389 against Duke Albrecht III, but later had to acknowledge him as their liege lord.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.at/ooe/oberoesterreich.html
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: 48.4230, 13.9911