| Castle Pines to Opwijk | 4,866.18 mi (7,831.35 km) |
| Castle Pines to Ostend | 4,812.22 mi (7,744.52 km) |
| Castle Pines to Oud-Heverlee | 4,888.30 mi (7,866.96 km) |
| Castle Pines to Oud-Turnhout | 4,877.59 mi (7,849.72 km) |
| Castle Pines to Oudenaarde | 4,851.53 mi (7,807.78 km) |
| Castle Pines to Oudenburg | 4,816.78 mi (7,751.86 km) |
| Castle Pines to Oupeye | 4,926.57 mi (7,928.55 km) |
| Castle Pines to Overijse | 4,886.01 mi (7,863.27 km) |
| Castle Pines to Overpelt | 4,896.41 mi (7,880.01 km) |
| Castle Pines to Paal | 4,896.16 mi (7,879.61 km) |
| Castle Pines to Peer | 4,901.36 mi (7,887.97 km) |
| Castle Pines to Pepinster | 4,938.70 mi (7,948.07 km) |
| Castle Pines to Peruwelz | 4,865.44 mi (7,830.16 km) |
| Castle Pines to Perwez | 4,902.52 mi (7,889.84 km) |
| Castle Pines to Philippeville | 4,912.26 mi (7,905.53 km) |
