The Fossa Carolina(1)
The Fossa Carolina is a cultural monument of European-wide importance. Located to the north of the village of Graben the “Graben” or dyke lends the village its name. In 793 Charlemagne wanted to connect the Danube and the Rhine rivers by a navigable channel between the Altmuehl and Rezat rivers. The dyke’s location was meticulously planned. Here both river systems are just 1800 metres apart and the highest point of the European watershed is only 12 meters above the level of the river Altmuehl.
Whether the Carolingian hydraulic engineers completely succeeded in their task is disputed. Historical sources tell us that there were long periods of heavy rains and unfavourable geological conditions that prevented the system’s completion but if it was unfinished it was probably due to political reasons. However, it is relatively certain that a connection between both river systems existed and was utilized, at least for a short while.
Visitors can enjoy a leisurely walk around the tree-lined embankment of the dyke. The fountain at the European Watershed on the dyke’s northern edge is a popular destination. The water from the fountain is channelled into two rivulets: one of them flows into the Fossa Carolina and then in the Altmuehl which flows into the Danube; the other one flows into the Rezat, then the Main and finally into the Rhine.
