Grasengrün was formerly part of the German Empire. In the German Empire, the place was called Grasengrün.
The place is now called Hájek and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Grasengrün | Austro-Hungary | Karlsbad | before the Treaty of Saint-Germain |
| Grasengrün | Czechoslovakia | Karlovy Vary | after the Treaty of Saint-Germain |
| Grasengrün | German Empire | Karlsbad | 1938 |
| Hájek | Czechoslovakia | Karlovy Vary | 1945 |
| Hájek | Czechoslovakia | Karlovy Vary | 1992 |
| Hájek | Czech Republic | Karlovy Vary | 1993 |