The remains of the Castle can be visited
Alt-Waldstein Castle

The Alt-Waldstein castle ruin is on an offshoot of the Schankkogel in Deutschfeistritz, Styria. Its strategic location once secured the passage from the Gleinalpe to the Upper Murtal.
History+
The origins of Alt-Waldstein Castle date back to the 12th century, with its construction likely undertaken by the noble family of St. Dionysen at the end of the 11th century. It was first documented in 1152 as "castrum waldstein." From 1190 to 1305, it was owned by the Lords of Wildon, followed by the Lords of Walsee, who expanded the complex into a fortress. In 1363, the castle passed to the Counts of Cilli, who held it until 1436.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.at
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: 47.2304, 15.2831