| Castel San Giorgio to Oerlinghausen | 823.78 mi (1,325.74 km) |
| Castel San Giorgio to Oestrich-Winkel | 714.30 mi (1,149.55 km) |
| Castel San Giorgio to Offenburg | 625.97 mi (1,007.40 km) |
| Castel San Giorgio to Oftersheim | 663.59 mi (1,067.94 km) |
| Castel San Giorgio to Ohrdruf | 719.57 mi (1,158.04 km) |
| Castel San Giorgio to Ohringen | 634.24 mi (1,020.71 km) |
| Castel San Giorgio to Olbernhau | 686.02 mi (1,104.04 km) |
| Castel San Giorgio to Olching | 538.75 mi (867.03 km) |
| Castel San Giorgio to Oldenburg | 906.23 mi (1,458.43 km) |
| Castel San Giorgio to Oldenburg in Holstein | 950.37 mi (1,529.47 km) |
| Castel San Giorgio to Olfen | 831.38 mi (1,337.98 km) |
| Castel San Giorgio to Olpe | 779.53 mi (1,254.53 km) |
| Castel San Giorgio to Olsberg | 787.86 mi (1,267.95 km) |
| Castel San Giorgio to Oranienburg | 829.97 mi (1,335.71 km) |
| Castel San Giorgio to Ortenberg | 715.01 mi (1,150.70 km) |
