The remains of the castle can be visited
Hauenfels Castle
The castle ruin Hauenfels, a former cave castle, is situated on the Ölberg near Gütighofen in the Breisgau-Hochschwarzwald region of Baden-Württemberg. Its peculiarity lies in its uncertain history and the fact that it was built into a rock overhang.
History+
The origins of Hauenfels Castle are largely unexplored, and it is debated whether it was actually a castle complex. The name "Hauenfels" is based on a misinterpretation of the term "Huwensteine," which would correctly mean "Owl Stone." A possible first mention as "Huwensteine" can be found in a court roll of St. Ulrich Monastery from 1316. Finds on site suggest a period of use from the 13th to the early 16th century. During the Thirty Years' War, the complex served as a hiding place for the Dominican Father Michael, from where he led a successful guerrilla war against the Swedes. Later, it was used as a hideout by robber gangs. In the late 1990s, parts of the masonry were damaged by vandalism.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Bau_am_%C3%96lberg_%28Burg_Hauenfels%29_01.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: 47.9186, 7.7676