Related Clues:
- Frankfurt's river
- Polish border river
- River to the North Sea
- Baltic Sea tributary
- River to the Baltic
- German river to the North Sea
- Part of the German/Polish border
- Wittenberg's river
- River of Brandenburg
- Frankfurt an der ___
- River of eastern Germany
- River through Opole
- European river
- German-Polish border river
- Germany's ___-Spree Canal