| Caernarfon to Opwijk | 388.98 mi (626.00 km) |
| Caernarfon to Ostend | 331.86 mi (534.07 km) |
| Caernarfon to Oud-Heverlee | 411.95 mi (662.97 km) |
| Caernarfon to Oud-Turnhout | 411.02 mi (661.48 km) |
| Caernarfon to Oudenaarde | 370.05 mi (595.54 km) |
| Caernarfon to Oudenburg | 336.29 mi (541.20 km) |
| Caernarfon to Oupeye | 454.11 mi (730.82 km) |
| Caernarfon to Overijse | 408.29 mi (657.07 km) |
| Caernarfon to Overpelt | 430.99 mi (693.61 km) |
| Caernarfon to Paal | 425.95 mi (685.50 km) |
| Caernarfon to Peer | 434.65 mi (699.50 km) |
| Caernarfon to Pepinster | 465.23 mi (748.72 km) |
| Caernarfon to Peruwelz | 380.90 mi (613.00 km) |
| Caernarfon to Perwez | 424.29 mi (682.82 km) |
| Caernarfon to Philippeville | 428.66 mi (689.86 km) |
