Gassöwen was formerly part of the German Empire. In the German Empire, the place was called Heidenberg *.
The place is now called NN and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Gassöwen | German Empire | Angerburg | 1914 |
| Heidenberg * | German Empire | Angerburg | 1939 |
| Gasewo | Under Polish administration | Węgorzewo | 1945 |
| NN | Poland | Suwałki | 1992 |