Julienthal was formerly part of the German Empire. In the German Empire, the place was called Julienthal.
The place is now called Lelek and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Julienthal | German Empire | Sensburg | 1939 |
| Lelek | Under Polish administration | Mrągowo | 1945 |
| Lelek | Poland | Suwałki | 1992 |