Waldmühle was formerly part of the German Empire. In the German Empire, the place was called Waldmühle.
The place is now called Ruda-Koźlanka and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Ruda-Kozlonka | German Empire | Wongrowitz | before the Versailles Treaty |
| Ruda-Koźlanka | Poland | Wągrowiec | after the Versailles Treaty |
| Waldmühle | German Empire | Eichenbrück | 1939 |
| Ruda-Koźlanka | Poland | Wągrowiec | 1945 |
| Ruda-Koźlanka | Poland | Poznań | 1992 |