![Abandoned mine Ofenkaulen](https://www.rhinedragon.de/wp-content/uploads/2017/08/678px_ofenkaulen.jpg)
Around the Ölberg
Ofenkaulen
The Ofenkaulen are a tunnel system, former underground tuff quarries in the Siebengebirge. Today, they are a winter quarters for bats. When you are halfway up the L 331 motorway that leads from Königswinter to Ittenbach you see the driveway to Mount Petersberg on your left side and a bus station on your right side.