The remains of the Castle can be visited
Gutenburg Castle (Ruin)

The Gutenburg ruin, a former hilltop castle, stands on a rocky spur at the edge of the Southern Black Forest, where the Schlücht valley transitions into the Klettgau. Its location on a granite hill made it a stronghold in the region.
History+
The origins of Gutenburg date back to the 10th century, when St. Gallen Abbey erected a tower to protect its possessions between the Alb and Schlücht rivers. In 1128, the abbey granted the tower and its lands as a fief to a noble family, who subsequently built a castle around the tower and considered it their property. A Rudolfus de Gutenburch was documented in 1128. From 1187, ownership passed to the Lords of Gutenburg, a ministerial family from Aargau, who gave the castle its name. The minnesinger Ulrich von Gutenburg may have lived here in the 13th century. In 1276, Conrad and Berchthold von Gutenburg sold numerous estates to St. Blasien Abbey. In the early 14th century, likely 1302, due to financial hardship, the castle passed from the descendants of Rudolf von Gutenburg to Heinrich II von Kränkingen.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 47.6553, 8.2503