The remains of the Castle can be visited
Kastelburg Castle

The Kastelburg castle ruin in Waldkirch, Baden-Württemberg, is a hilltop castle.
History+
The construction of Kastelburg took place between 1260 and 1270 by the Lords of Schwarzenberg. Its strategic location allowed for the defense of Waldkirch and the monitoring of the important trade route through the Elztal. Johann I von Schwarzenberg was the first resident of this complex. After the Schwarzenberg line died out in 1345, the castle passed to Martin Malterer from Freiburg, who fell in the Battle of Sempach in 1386. In 1429, ownership transferred to Berthold von Staufen.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://de.wikipedia.org/wiki/Datei:Luftaufnahme-Kastelburg-26102005.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: 48.0975, 7.9579