| Castle Rock to Octeville | 4,722.71 mi (7,600.46 km) |
| Castle Rock to Oignies | 4,851.26 mi (7,807.35 km) |
| Castle Rock to Oissel | 4,832.76 mi (7,777.58 km) |
| Castle Rock to Olivet | 4,924.92 mi (7,925.89 km) |
| Castle Rock to Ollioules | 5,281.69 mi (8,500.07 km) |
| Castle Rock to Olonne-sur-Mer | 4,844.55 mi (7,796.56 km) |
| Castle Rock to Oloron-Sainte-Marie | 5,030.65 mi (8,096.05 km) |
| Castle Rock to Onet Village | 5,103.52 mi (8,213.32 km) |
| Castle Rock to Onnaing | 4,875.53 mi (7,846.41 km) |
| Castle Rock to Orange | 5,197.10 mi (8,363.93 km) |
| Castle Rock to Orchies | 4,859.63 mi (7,820.82 km) |
| Castle Rock to Orleans | 4,923.56 mi (7,923.70 km) |
| Castle Rock to Orly | 4,904.63 mi (7,893.24 km) |
| Castle Rock to Ormesson-sur-Marne | 4,907.99 mi (7,898.65 km) |
| Castle Rock to Orsay | 4,899.29 mi (7,884.65 km) |
