Aachtopf
The Aachtopf is Germany's biggest spring in terms of production, which is 8.500 liter per second in average. It is a karst spring which is located south of the western end of the Swabian Jura, near the town Aach, Baden-Württemberg. As a typical karst spring the production depends very much on the season and the weather but it never falls dry.
The name Aachtopf is built of Aach, the name of the river which springs here, and Topf which translates bowl and is commonly used for round, bowl-shaped springs. The Aach is flowing southwards and soon merges with the Rhine. The spring is the southern end of a cave system which transports water from the western end of the Swabian Jura. Most of the water is originally Danube water which sinks near Immendingen and near Fridingen. The strange fact is, that Danube water flows eastwards and disembogues into the Black Sea, whereas Aach and Rhine flow northwards to the North Sea.
The karst spring is connected to a huge cave which runs northwards. As it is completely water-filled it is explored only by cave divers. The first exploration was made by
