| Gravelines to Opwijk | 89.44 mi (143.94 km) |
| Gravelines to Ostend | 38.13 mi (61.36 km) |
| Gravelines to Oud-Heverlee | 111.12 mi (178.83 km) |
| Gravelines to Oud-Turnhout | 125.85 mi (202.53 km) |
| Gravelines to Oudenaarde | 64.83 mi (104.33 km) |
| Gravelines to Oudenburg | 40.24 mi (64.76 km) |
| Gravelines to Oupeye | 154.55 mi (248.73 km) |
| Gravelines to Overijse | 105.80 mi (170.27 km) |
| Gravelines to Overpelt | 143.58 mi (231.07 km) |
| Gravelines to Paal | 132.42 mi (213.11 km) |
| Gravelines to Peer | 144.78 mi (233.00 km) |
| Gravelines to Pepinster | 163.75 mi (263.54 km) |
| Gravelines to Peruwelz | 71.43 mi (114.96 km) |
| Gravelines to Perwez | 119.98 mi (193.09 km) |
| Gravelines to Philippeville | 119.33 mi (192.05 km) |
