The Old Bavarian Donaumoos (German: Altbayerisches Donaumoos) is an old fen on the southern side of the Danube, southwest of Ingolstadt, Bavaria, in the Neuburg-Schrobenhausen district. The fen, drained from 1790 onwards, has now dropped 3 metres (9.8 ft) in surface level because of the drainage and associated environmental effects.