English Aachtopf Cited by user Dave.Dunford on 21 Jun 2021 The is Germany's biggest karst spring, south of the western end of the Swabian Jura near the town of Aach.
English Danube Sinkhole Cited by user HansM on 29 Jun 2011 The Danube Sinkhole is an incipient underground stream capture in the Upper Danube Nature Park.