The remains of the Castle can be visited
Hinterburg Castle
Hinterburg Castle Ruin is on a narrow rock outcrop near Tengen in the Konstanz district. It is a hilltop castle.
History+
The construction of Hinterburg Castle took place around 1150 by the Barons of Tengen, who later became counts. In the mid-13th century, the front part of the mountain spur was used for the planned establishment of a town. During a division of the lordship around 1275, the extensive castle area was separated as the “Hinterburg”. After several changes of ownership, the complex came into the possession of the Teutonic Order Commandery of Mainau. Hinterburg suffered destruction after 1442 by an army of the Swabian League of Cities and was again devastated by the Confederates in 1457.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Burg_Tengen_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: 47.8116, 8.6587