The Bruchhauser Steine are four porphyry rocks on the Istenberg: Bornstein, Feldstein, Goldstein and Ravenstein. Since 2017 they have been a National Natural Monument. Only the Feldstein may be climbed, and you'll need sturdy shoes. Dogs on a lead are welcome, but not on the Feldstein itself. The circular walk isn't wheelchair accessible, though the short gravel path is fine for pushchairs. Check the current opening times before you go, as they vary by season.