| Castro Daire to Octeville | 675.55 mi (1,087.19 km) |
| Castro Daire to Oignies | 843.92 mi (1,358.17 km) |
| Castro Daire to Oissel | 729.51 mi (1,174.03 km) |
| Castro Daire to Olivet | 682.58 mi (1,098.51 km) |
| Castro Daire to Ollioules | 723.17 mi (1,163.83 km) |
| Castro Daire to Olonne-sur-Mer | 495.94 mi (798.14 km) |
| Castro Daire to Oloron-Sainte-Marie | 407.78 mi (656.26 km) |
| Castro Daire to Onet Village | 585.66 mi (942.53 km) |
| Castro Daire to Onnaing | 858.21 mi (1,381.16 km) |
| Castro Daire to Orange | 685.56 mi (1,103.31 km) |
| Castro Daire to Orchies | 851.72 mi (1,370.70 km) |
| Castro Daire to Orleans | 684.63 mi (1,101.81 km) |
| Castro Daire to Orly | 740.19 mi (1,191.23 km) |
| Castro Daire to Ormesson-sur-Marne | 747.01 mi (1,202.20 km) |
| Castro Daire to Orsay | 731.22 mi (1,176.79 km) |
