The remains of the Castle can be visited
Klamleiten Castle

In Alberndorf in Upper Austria, the Klamleiten Castle Ruin, a former hilltop castle, stands on a rocky spur. Its strategic location suggests a past importance for protecting the surrounding routes.
History+
The first documented mention of Klamleiten Castle dates back to 1292. In 1408, there is a reference to a "Tvrnlein pey der Gusen," indicating a tower near the Gusen river. The fortification likely served to protect the roads of that time. Its destruction is attributed to the Hussites, who invaded the Mühlviertel region in 1427, conquering and devastating numerous castles. An alternative theory suggests that the castle was destroyed later, in 1477, by Emperor Frederick III.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Alberndorf_in_der_Riedmark_-_Klamleiten_%28Burgruine_Klamleiten-1%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: 48.4036, 14.3976