| Castro Daire to Opwijk | 904.69 mi (1,455.96 km) |
| Castro Daire to Ostend | 881.01 mi (1,417.85 km) |
| Castro Daire to Oud-Heverlee | 913.18 mi (1,469.63 km) |
| Castro Daire to Oud-Turnhout | 946.31 mi (1,522.95 km) |
| Castro Daire to Oudenaarde | 881.28 mi (1,418.28 km) |
| Castro Daire to Oudenburg | 881.03 mi (1,417.88 km) |
| Castro Daire to Oupeye | 938.87 mi (1,510.96 km) |
| Castro Daire to Overijse | 906.59 mi (1,459.02 km) |
| Castro Daire to Overpelt | 955.06 mi (1,537.03 km) |
| Castro Daire to Paal | 938.96 mi (1,511.11 km) |
| Castro Daire to Peer | 952.29 mi (1,532.56 km) |
| Castro Daire to Pepinster | 938.30 mi (1,510.04 km) |
| Castro Daire to Peruwelz | 864.12 mi (1,390.67 km) |
| Castro Daire to Perwez | 907.98 mi (1,461.26 km) |
| Castro Daire to Philippeville | 879.59 mi (1,415.56 km) |
