| Castelleone to Opwijk | 468.40 mi (753.81 km) |
| Castelleone to Ostend | 516.16 mi (830.68 km) |
| Castelleone to Oud-Heverlee | 448.88 mi (722.40 km) |
| Castelleone to Oud-Turnhout | 470.15 mi (756.63 km) |
| Castelleone to Oudenaarde | 477.31 mi (768.16 km) |
| Castelleone to Oudenburg | 511.67 mi (823.45 km) |
| Castelleone to Oupeye | 419.47 mi (675.07 km) |
| Castelleone to Overijse | 449.27 mi (723.03 km) |
| Castelleone to Overpelt | 455.10 mi (732.41 km) |
| Castelleone to Paal | 449.43 mi (723.29 km) |
| Castelleone to Peer | 449.22 mi (722.96 km) |
| Castelleone to Pepinster | 407.25 mi (655.41 km) |
| Castelleone to Peruwelz | 460.09 mi (740.45 km) |
| Castelleone to Perwez | 433.25 mi (697.25 km) |
| Castelleone to Philippeville | 416.22 mi (669.84 km) |
