| Castel San Giovanni to Opwijk | 475.13 mi (764.64 km) |
| Castel San Giovanni to Ostend | 521.36 mi (839.05 km) |
| Castel San Giovanni to Oud-Heverlee | 456.22 mi (734.21 km) |
| Castel San Giovanni to Oud-Turnhout | 478.85 mi (770.63 km) |
| Castel San Giovanni to Oudenaarde | 482.85 mi (777.06 km) |
| Castel San Giovanni to Oudenburg | 516.91 mi (831.88 km) |
| Castel San Giovanni to Oupeye | 428.45 mi (689.52 km) |
| Castel San Giovanni to Overijse | 456.28 mi (734.31 km) |
| Castel San Giovanni to Overpelt | 464.42 mi (747.41 km) |
| Castel San Giovanni to Paal | 458.04 mi (737.14 km) |
| Castel San Giovanni to Peer | 458.49 mi (737.87 km) |
| Castel San Giovanni to Pepinster | 416.35 mi (670.05 km) |
| Castel San Giovanni to Peruwelz | 464.90 mi (748.19 km) |
| Castel San Giovanni to Perwez | 440.48 mi (708.88 km) |
| Castel San Giovanni to Philippeville | 422.08 mi (679.27 km) |
