To be privately owned
Achleiten Castle

Achleiten Castle, once a summer residence for Benedictine monks, stands in the northwest of Limbach, a cadastral community of Strengberg, in the Amstetten district of Lower Austria. Today, it serves as a private estate.
History+
The origins of the lands date back a long way. Even before 1011, the Bavarian Benedictine monastery of Tegernsee owned land here. Through an exchange of goods with King Henry II, the monastery was able to expand its possessions by 60 royal hides and established the dominion of Achleiten. However, the original center of this dominion, a fortified complex with towers near the Danube, was frequently threatened by floods. Therefore, Abbot Gregor I. Plaichshirn had the current castle built on a higher, safer site between 1727 and 1734. It served as a summer residence for the Tegernsee Benedictines until 1803.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Hans Koberger / CC BY-SA 4.0 via Wikimedia Commons
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: 48.1521, 14.6563