Hartau was formerly part of the German Empire. In the German Empire, the place was called Hartau.
The place is now called Opoka (Wałbrzych-Opoka) and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Hartau | German Empire | Waldenburg (Schles.) | 1939 |
| Opoka | Under Polish administration | Wałbrzych m. | 1945 |
| Opoka (Wałbrzych-Opoka) | Poland | Wałbrzych | 1992 |