The remains of the Castle can be visited
Heidenlöcher Castle
Above the small Palatinate town of Deidesheim are the remains of the Heidenlöcher castle ruin. It was a refuge castle from the Carolingian or Ottonian period, which once offered protection. Today, it is a cultural monument in Rhineland-Palatinate.
History+
The Heidenlöcher were presumably built in the 9th or 10th century through forced labor. Its primary function was to offer protection to the surrounding inhabitants from Norman raids. There is no evidence of violent destruction; the current ruined state is due to the natural decay of the archaeological remains discovered in the early 19th century. The refuge castle first gained public attention in the 1820s through local history enthusiasts. Between 1907 and 1908, excavations were carried out under the direction of Friedrich Sprater from the Historical Museum of the Palatinate.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Heidenloechertor.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: 49.4155, 8.1647