The Regen is a river in Bavaria, Germany. Its source is located in the Bohemian Forest on the territory of the Czech Republic. Shortly after the river, which is called Black Regen (Schwarzer Regen) in this section, crosses the border. Close to the small town of K鰐zting it is joined by the White Regen (Wei遝r Regen).
The Regen forms the main valley crossing the Bavarian Forest; many settlements within that mountain range are located along the river. Cities along the Regen river include Cham, Regen and Regensburg. At Regensburg the river meets the Danube.
In 1999, transport on the river was made difficult by the NATO bombing of 3 bridges in Serbia.
Since the Rhine is the only river rising in the Alps mountains which flows north towards the North Sea, an invisible line divides large parts of southern Germany, which is sometimes referred to as the European Watershed.
Downstream from the Freudenau Locks in Vienna, canalization of the Danube was limited to the Gab膷铆kovo dam and locks near Bratislava and the two double Iron Gate locks in the border stretch of the Danube between Serbia and Romania.