| Blackrock to Oerlinghausen | 628.09 mi (1,010.82 km) |
| Blackrock to Oestrich-Winkel | 647.84 mi (1,042.59 km) |
| Blackrock to Offenburg | 698.25 mi (1,123.73 km) |
| Blackrock to Oftersheim | 691.06 mi (1,112.15 km) |
| Blackrock to Ohrdruf | 736.45 mi (1,185.20 km) |
| Blackrock to Ohringen | 732.90 mi (1,179.49 km) |
| Blackrock to Olbernhau | 847.12 mi (1,363.31 km) |
| Blackrock to Olching | 839.21 mi (1,350.57 km) |
| Blackrock to Oldenburg | 594.43 mi (956.64 km) |
| Blackrock to Oldenburg in Holstein | 697.88 mi (1,123.13 km) |
| Blackrock to Olfen | 579.76 mi (933.04 km) |
| Blackrock to Olpe | 613.39 mi (987.15 km) |
| Blackrock to Olsberg | 632.41 mi (1,017.76 km) |
| Blackrock to Oranienburg | 805.16 mi (1,295.79 km) |
| Blackrock to Ortenberg | 680.03 mi (1,094.40 km) |
