Brettgrund was formerly part of the German Empire. In the German Empire, the place was called Brettgrund.
The place is now called Prkenný Důl and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Brettgrund | Austro-Hungary | Trautenau | before the Treaty of Saint-Germain |
| Prkenný Důl | Czechoslovakia | Trutnov | after the Treaty of Saint-Germain |
| Brettgrund | Czechoslovakia | Trutnov | after the Treaty of Saint-Germain |
| Brettgrund | German Empire | Trautenau | 1938 |
| Prkenný Důl | Czechoslovakia | Trutnov | 1945 |
| Prkenný Důl | Czechoslovakia | Trutnov | 1992 |
| Prkenný Důl | Czech Republic | Trutnov | 1993 |