Ziernsee
Ziernsee is a lake in the Mecklenburg Lake District, in Germany. Whilst most of the lake is in the district of Mecklenburgische Seenplatte (municipality Priepert) in the state of Mecklenburg-Vorpommern, a portion of its southern shore is in the state of Brandenburg. The lake has an elevation of  and a surface area of . The navigable River Havel flows through the Ziernsee, entering it via a  long channel from the Ellbogensee to the west, and exiting via a  channel to the Röblinsee. Navigation is administered as part of the Obere–Havel–Wasserstraße. References 

Lakes of Mecklenburg-Western Pomerania
Lakes of Brandenburg
Federal waterways in Germany