| Castel Volturno to Oerlinghausen | 793.98 mi (1,277.79 km) |
| Castel Volturno to Oestrich-Winkel | 680.96 mi (1,095.90 km) |
| Castel Volturno to Offenburg | 590.14 mi (949.73 km) |
| Castel Volturno to Oftersheim | 630.37 mi (1,014.48 km) |
| Castel Volturno to Ohrdruf | 692.53 mi (1,114.52 km) |
| Castel Volturno to Ohringen | 602.60 mi (969.79 km) |
| Castel Volturno to Olbernhau | 665.04 mi (1,070.27 km) |
| Castel Volturno to Olching | 510.21 mi (821.11 km) |
| Castel Volturno to Oldenburg | 876.90 mi (1,411.24 km) |
| Castel Volturno to Oldenburg in Holstein | 926.08 mi (1,490.38 km) |
| Castel Volturno to Olfen | 799.29 mi (1,286.34 km) |
| Castel Volturno to Olpe | 747.27 mi (1,202.62 km) |
| Castel Volturno to Olsberg | 757.08 mi (1,218.41 km) |
| Castel Volturno to Oranienburg | 809.32 mi (1,302.48 km) |
| Castel Volturno to Ortenberg | 684.04 mi (1,100.86 km) |
