The remains of the Castle can be visited
Engelburg Castle
The Engelburg castle ruin, once also known as Biberburg, is a historical site on a hill above the Stuttgart district of Mühlhausen.
History+
The origins of the Engelburg possibly go back to a Biberburg mentioned in documents around 700, belonging to the Alamannic Duke Gottfried. Between 1260 and 1280, a new castle complex was built on this site, its construction presumably attributed to the Lords of Blankenstein. Another theory suggests that the castle's name might derive from Engelbold, the last descendant of the Lords of Kaltental. Its fate was sealed in 1312, when the castle was destroyed during the Imperial and Cities War.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://schloesserrundschau.de/bawue/schloesser/engelburg.html
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: 48.8432, 9.2281