| Castano Primo to Opwijk | 429.36 mi (690.99 km) |
| Castano Primo to Ostend | 474.82 mi (764.15 km) |
| Castano Primo to Oud-Heverlee | 410.84 mi (661.18 km) |
| Castano Primo to Oud-Turnhout | 434.41 mi (699.11 km) |
| Castano Primo to Oudenaarde | 436.46 mi (702.42 km) |
| Castano Primo to Oudenburg | 470.38 mi (757.01 km) |
| Castano Primo to Oupeye | 384.32 mi (618.51 km) |
| Castano Primo to Overijse | 410.69 mi (660.95 km) |
| Castano Primo to Overpelt | 420.51 mi (676.75 km) |
| Castano Primo to Paal | 413.56 mi (665.56 km) |
| Castano Primo to Peer | 414.55 mi (667.15 km) |
| Castano Primo to Pepinster | 372.35 mi (599.24 km) |
| Castano Primo to Peruwelz | 418.24 mi (673.09 km) |
| Castano Primo to Perwez | 395.05 mi (635.78 km) |
| Castano Primo to Philippeville | 375.91 mi (604.96 km) |
