The remains of the Castle can be visited
CastleBonndorf-Wittlekofen
Roggenbach Castle (Ruin)

The Roggenbach ruin is on a ridge near Bonndorf-Wittlekofen in the Waldshut district. The complex once encompassed two towers.
History+
Around the year 1200, the hilltop castle was erected by the Counts of Nellenburg. Its first documented mention dates back to 1288 in connection with a sale. In 1525, Roggenbach Castle, similar to the neighboring Steinegg Castle, was destroyed during the Peasants' War. The complex consisted of two parts, each with a tower, which at times belonged to different knightly families.
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: 47.7684, 8.3377