The remains of the Castle can be visited
Zeiselberg Castle

On a hill above the village of Zeiselberg in the municipality of Magdalensberg in Carinthia, Austria, lies the castle ruin Zeiselberg, a medieval fortress. Its history is brief, as it presumably existed for only a few decades before its destruction.
History+
The Zeiselberger family, ministeriales of the Carinthian dukes and a branch of the Freibergers, is first documented in 1202. The castle itself was first mentioned in documents in 1250, when it was owned by the Lords of Zeisel. Under Albert de Zeyselberg, who served as the supreme judge in Carinthia between 1267 and 1269, a new construction took place in the second half of the 13th century. After Albert's death in the 1270s, the male line of the Zeiselberger family died out.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Magdalensberg_Zeiselberg_Zeiselburg_06102006_776.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: 46.6626, 14.3841