The remains of the Castle can be visited
Bertholdstein Castle

The ruin Bertholdstein is the ruin of a hilltop castle near Hollenburg in Lower Austria (today part of the municipality of Krems an der Donau).
In the 12th century, the Bishop of Freising pushed for the establishment of a separate parish in Hollenburg, and a successor had his castle built west of the village in the 13th century. Under Bishop Berthold von Wehingen (1381–1410), the castle complex was expanded; the castle is named Bertholdstein after him. Due to acts of war, there were repeated destructions over the centuries; after the Swedes in 1645/46 and the Turks in 1683, the plague broke out, and a fire in 1698 largely destroyed the complex, which has been a ruin ever since.
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Location: 48.3797, 15.6804