The remains of the castle can be visited
Freudenstein Castle

The Freudenstein Castle Ruin, a former medieval ministerial castle, is located on a rocky spur in Feldkirchen an der Donau in the Urfahr-Umgebung district, Upper Austria.
History+
The first documented mention of Freudenstein Castle was in 1278, when Heinrich von Lichtenhag granted it to Ulrich von Lobenstein. Just six years later, in 1284, the castle, then owned by Konrad von Sumerau, was conquered by Duke Albrecht I. Around 1303, it belonged to the Niedernburg Monastery near Passau. A document from 1308 confirms that Freudenstein later came into the possession of the Piber zu Lobenstein. In 1333, the brothers Ulrich and Friedrich Prüschenkh sold the complex to Eberhard von Wallsee, a captain in the country above the Enns. He was commissioned by the Habsburgs to break the power of the Schaunberger. Despite the resistance of Count Heinrich von Schaunberg, whose ancestral seat was nearby, Duke Albrecht of Austria decided that the castle should remain with the Wallsee family. Eberhard von Wallsee appointed burgraves, including Trentzlin Walch, Hans Prembser (1376), and Hans Taumichler (1396).
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Feldkirchen_an_der_Donau_%28Burgruine_Freudenstein-2%29.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: 48.3519, 14.0968