| Castle Rock to Oerlinghausen | 4,972.15 mi (8,001.90 km) |
| Castle Rock to Oestrich-Winkel | 5,041.15 mi (8,112.95 km) |
| Castle Rock to Offenburg | 5,109.79 mi (8,223.41 km) |
| Castle Rock to Oftersheim | 5,089.70 mi (8,191.08 km) |
| Castle Rock to Ohrdruf | 5,090.95 mi (8,193.09 km) |
| Castle Rock to Ohringen | 5,128.03 mi (8,252.76 km) |
| Castle Rock to Olbernhau | 5,180.14 mi (8,336.63 km) |
| Castle Rock to Olching | 5,235.66 mi (8,425.98 km) |
| Castle Rock to Oldenburg | 4,904.00 mi (7,892.22 km) |
| Castle Rock to Oldenburg in Holstein | 4,931.75 mi (7,936.89 km) |
| Castle Rock to Olfen | 4,942.49 mi (7,954.17 km) |
| Castle Rock to Olpe | 4,988.98 mi (8,028.99 km) |
| Castle Rock to Olsberg | 4,994.70 mi (8,038.20 km) |
| Castle Rock to Oranienburg | 5,075.40 mi (8,168.07 km) |
| Castle Rock to Ortenberg | 5,059.29 mi (8,142.14 km) |
