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

The Mandach Ruin, also known as Weiler Castle, stands on a rocky spur above the Mettma Valley near Ühlingen-Birkendorf. Only a few remnants of the former complex remain today.
History+
The origins of Mandach Castle are largely unknown. It was first documented around 1352 in connection with Heinrich von Erzingen. The von Erzingen family owned the castle until their extinction around 1501, after which it was sold to Junker Lukas von Reischach. He then sold the complex to St. Blasien Monastery, which subsequently managed it through bailiffs. In 1581, Christoph von Mandach took up residence at Weiler Castle. He died around 1616, and his widow Euphrosine bequeathed her rights to Riedern am Wald Monastery in 1610. It is assumed that the castle was abandoned thereafter. The name Mandach was probably derived from this family.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Buchstapler / CC BY-SA 4.0 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: 47.7068, 8.2760