| Castle Pines to Octeville | 4,718.95 mi (7,594.42 km) |
| Castle Pines to Oignies | 4,847.29 mi (7,800.97 km) |
| Castle Pines to Oissel | 4,828.93 mi (7,771.42 km) |
| Castle Pines to Olivet | 4,921.16 mi (7,919.85 km) |
| Castle Pines to Ollioules | 5,278.09 mi (8,494.27 km) |
| Castle Pines to Olonne-sur-Mer | 4,841.03 mi (7,790.88 km) |
| Castle Pines to Oloron-Sainte-Marie | 5,027.32 mi (8,090.68 km) |
| Castle Pines to Onet Village | 5,099.97 mi (8,207.61 km) |
| Castle Pines to Onnaing | 4,871.55 mi (7,840.00 km) |
| Castle Pines to Orange | 5,193.48 mi (8,358.10 km) |
| Castle Pines to Orchies | 4,855.66 mi (7,814.42 km) |
| Castle Pines to Orleans | 4,919.80 mi (7,917.65 km) |
| Castle Pines to Orly | 4,900.80 mi (7,887.07 km) |
| Castle Pines to Ormesson-sur-Marne | 4,904.15 mi (7,892.47 km) |
| Castle Pines to Orsay | 4,895.47 mi (7,878.50 km) |
