boardwalk alongside natural stone water channel in forest

alongside anomaly attraction bed board boardwalk calcareous carbonate causeway channel course creek dam destination environment explore exploration feature flow flowing footbridge footpath forest formation geographical geologic geological germany groove gully increasing kalksockel landmark lime limestone lithic miracle monument moss natural nature path petrified phenomena planked preserve protect protected protection reserve rill rinne rivulet runlet runnel running scale sinter site steinerne stone streamlet syncline trail trough tufa tufaceous unique value walk walkway water watercourse waters way winding wood wooden woods park