In sedimentary-deposits of the Nahe river agate- and jasper-pebbles can be found. The river loops in the proximity of the tunnel break-throughs  for railway and road in the east of Oberstein offer a place of discovery of this kind. This range is called “fallen rock”. Here a giantful monolith leaned at the mountain with a height of approximately 90m, that was completely detached from the hostrock. Unfortunately this geological sensation was blown away with the building of the road tunnel.