| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Opera castellana del Castello di Croglio | city | Ticino | Switzerland | 45.99 | 8.84 | 1906 | 28152 |
| Opera castellano del Castello di San Martino | city | Ticino | Switzerland | 45.98 | 8.96 | 830 | 75677 |
| Opfike | city | Zurich | Switzerland | 47.43 | 8.58 | 1669 | 160852 |
| Opfikon | city | Zurich | Switzerland | 47.43 | 8.58 | 1669 | 160852 |
| Opfikon-Glattbrugg | city | Zurich | Switzerland | 47.43 | 8.58 | 1669 | 160852 |
| Oppens | city | Vaud | Switzerland | 46.72 | 6.69 | 1873 | 5967 |