| Castrop-Rauxel to Opwijk | 141.34 mi (227.46 km) |
| Castrop-Rauxel to Ostend | 190.89 mi (307.21 km) |
| Castrop-Rauxel to Oud-Heverlee | 124.97 mi (201.12 km) |
| Castrop-Rauxel to Oud-Turnhout | 101.79 mi (163.81 km) |
| Castrop-Rauxel to Oudenaarde | 168.00 mi (270.37 km) |
| Castrop-Rauxel to Oudenburg | 187.90 mi (302.39 km) |
| Castrop-Rauxel to Oupeye | 92.99 mi (149.66 km) |
| Castrop-Rauxel to Overijse | 131.70 mi (211.96 km) |
| Castrop-Rauxel to Overpelt | 85.10 mi (136.96 km) |
| Castrop-Rauxel to Paal | 99.12 mi (159.52 km) |
| Castrop-Rauxel to Peer | 85.42 mi (137.47 km) |
| Castrop-Rauxel to Pepinster | 94.12 mi (151.47 km) |
| Castrop-Rauxel to Peruwelz | 177.21 mi (285.19 km) |
| Castrop-Rauxel to Perwez | 126.01 mi (202.79 km) |
| Castrop-Rauxel to Philippeville | 152.46 mi (245.37 km) |
