Frauenau is a municipality in the district of Regen, in Bavaria, Germany. It is known for its artificial lake, which is used as a water supply of the area around Deggendorf and Passau.

Regen is a Landkreis in Bavaria, Germany. It is bounded by the districts of Freyung-Grafenau, Deggendorf, Straubing-Bogen and Cham, and by the Czech Republic.