| Castel Bolognese to Opwijk | 579.73 mi (932.98 km) |
| Castel Bolognese to Ostend | 629.92 mi (1,013.77 km) |
| Castel Bolognese to Oud-Heverlee | 559.16 mi (899.88 km) |
| Castel Bolognese to Oud-Turnhout | 577.32 mi (929.11 km) |
| Castel Bolognese to Oudenaarde | 590.72 mi (950.67 km) |
| Castel Bolognese to Oudenburg | 625.39 mi (1,006.46 km) |
| Castel Bolognese to Oupeye | 526.45 mi (847.24 km) |
| Castel Bolognese to Overijse | 560.20 mi (901.55 km) |
| Castel Bolognese to Overpelt | 560.91 mi (902.70 km) |
| Castel Bolognese to Paal | 556.98 mi (896.37 km) |
| Castel Bolognese to Peer | 555.23 mi (893.55 km) |
| Castel Bolognese to Pepinster | 514.07 mi (827.31 km) |
| Castel Bolognese to Peruwelz | 574.71 mi (924.90 km) |
| Castel Bolognese to Perwez | 543.86 mi (875.26 km) |
| Castel Bolognese to Philippeville | 529.42 mi (852.01 km) |
