The remains of the castle can be visited
Staufen Castle

The Staufen castle ruin sits atop a conical hill on the northeastern edge of Hilzingen. Once a medieval hilltop castle, it is now freely accessible.
History+
The history of Staufen Castle dates back to the Middle Ages. From around 1269, the castle complex and its hill were held as a fief by the Lords of Homburg. For a time, it was a fief of the Counts of Hohenberg, before being taken over by the Dukes of Austria in 1381. In the Swiss War of 1499, the castle was set ablaze by the Confederates.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Hubenschmid / CC BY-SA 3.0 via Wikimedia Commons
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: 47.7722, 8.8033