The remains of the Castle can be visited
Waldenburg Castle
The Waldenburg castle ruin stands on a ridge above the Enz river at the entrance to Neuenbürg. This hilltop castle in Baden-Württemberg is shrouded in mystery, as its origins and history are largely unknown.
History+
The past of Waldenburg Castle remains an enigma to this day. Despite research, excavations, and archaeological investigations, no written records or documents have been found that could shed light on its creation or use. Only a few pottery finds suggest connections to the Upper Rhine and the Swabian Alb.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Ruine_Waldenburg1.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: 48.8414, 8.5950