| Castrolibero to Opwijk | 992.72 mi (1,597.63 km) |
| Castrolibero to Ostend | 1,042.60 mi (1,677.91 km) |
| Castrolibero to Oud-Heverlee | 972.12 mi (1,564.47 km) |
| Castrolibero to Oud-Turnhout | 989.71 mi (1,592.78 km) |
| Castrolibero to Oudenaarde | 1,003.47 mi (1,614.93 km) |
| Castrolibero to Oudenburg | 1,038.08 mi (1,670.62 km) |
| Castrolibero to Oupeye | 938.89 mi (1,511.00 km) |
| Castrolibero to Overijse | 973.19 mi (1,566.19 km) |
| Castrolibero to Overpelt | 972.92 mi (1,565.76 km) |
| Castrolibero to Paal | 969.50 mi (1,560.27 km) |
| Castrolibero to Peer | 967.31 mi (1,556.73 km) |
| Castrolibero to Pepinster | 926.50 mi (1,491.05 km) |
| Castrolibero to Peruwelz | 987.06 mi (1,588.52 km) |
| Castrolibero to Perwez | 956.85 mi (1,539.89 km) |
| Castrolibero to Philippeville | 942.18 mi (1,516.29 km) |
