The remains of the Castle can be visited
Sausenburg Castle

The Sausenburg castle ruin, once the ancestral castle of the Lords of Sausenburg, stands on a peak in the Lörrach district.
History+
The origins of Sausenburg date back to a time when lands on the Sausenburg passed from the Lords of Kaltenbach to St. Blasien Monastery at the beginning of the 12th century. In 1306, Margrave Rudolf I became the founder of the Hachberg-Sausenburg line. In 1232, the Margraves of Hachberg, who already held the vogtei over the provostries of Bürgeln and Sitzenkirch, acquired the Sausenburg lordship from the monastery. They built the castle to secure the territory and took up residence there from 1246.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: https://de.wikipedia.org/wiki/Datei:Sausenburg_07200601.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: 47.7379, 7.6892