Rettkau
Rettkau is a German place name:
- Rettkau (Ostpr.) , Until 1938 Rettkowen , village in the Neidenburg district, East Prussia, from 1945: Retkowo (Janowo) , lost place in the powiat Nidzicki, Warmian-Masurian Voivodeship, Poland
- Rettkau , village in the district of Glogau, Silesia, since 1945: Retków (Grębocice) in Powiat Polkowicki, Lower Silesian Voivodeship, Poland