| Castel Volturno to Oberkirch | 590.47 mi (950.27 km) |
| Castel Volturno to Obernburg am Main | 649.61 mi (1,045.44 km) |
| Castel Volturno to Obernkirchen | 807.24 mi (1,299.13 km) |
| Castel Volturno to Oberschleissheim | 510.64 mi (821.79 km) |
| Castel Volturno to Oberstdorf | 474.74 mi (764.03 km) |
| Castel Volturno to Obertraubling | 553.53 mi (890.81 km) |
| Castel Volturno to Obertshausen | 669.38 mi (1,077.26 km) |
| Castel Volturno to Oberursel | 682.59 mi (1,098.52 km) |
| Castel Volturno to Ochsenfurt | 622.70 mi (1,002.13 km) |
| Castel Volturno to Ochsenhausen | 522.86 mi (841.46 km) |
| Castel Volturno to Ochtrup | 833.36 mi (1,341.17 km) |
| Castel Volturno to Odenthal | 762.20 mi (1,226.64 km) |
| Castel Volturno to Oelde | 793.41 mi (1,276.86 km) |
| Castel Volturno to Oelsnitz | 652.61 mi (1,050.27 km) |
| Castel Volturno to Oer-Erkenschwick | 797.11 mi (1,282.83 km) |
