Ostrov was formerly part of the German Empire. In the German Empire, the place was called Wörles.
The place is now called NN and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Wörles | Austro-Hungary | Kaplitz | before the Treaty of Saint-Germain |
| Ostrov | Czechoslovakia | Kaplice | after the Treaty of Saint-Germain |
| Wörles | Czechoslovakia | Kaplice | after the Treaty of Saint-Germain |
| Wörles | German Empire | Kaplitz | 1938 |
| Ostrov | Czechoslovakia | Kaplice | 1945 |
| Ostrov | Czechoslovakia | Český Krumlov | 1992 |
| NN | Czech Republic | Český Krumlov | 1993 |