| Upper Grand Lagoon to Oerlinghausen | 4,782.12 mi (7,696.08 km) |
| Upper Grand Lagoon to Oestrich-Winkel | 4,808.26 mi (7,738.15 km) |
| Upper Grand Lagoon to Offenburg | 4,847.30 mi (7,800.98 km) |
| Upper Grand Lagoon to Oftersheim | 4,849.47 mi (7,804.47 km) |
| Upper Grand Lagoon to Ohrdruf | 4,895.28 mi (7,878.19 km) |
| Upper Grand Lagoon to Ohringen | 4,891.96 mi (7,872.84 km) |
| Upper Grand Lagoon to Olbernhau | 5,002.69 mi (8,051.05 km) |
| Upper Grand Lagoon to Olching | 4,996.25 mi (8,040.68 km) |
| Upper Grand Lagoon to Oldenburg | 4,733.53 mi (7,617.88 km) |
| Upper Grand Lagoon to Oldenburg in Holstein | 4,803.20 mi (7,730.01 km) |
| Upper Grand Lagoon to Olfen | 4,738.04 mi (7,625.13 km) |
| Upper Grand Lagoon to Olpe | 4,774.32 mi (7,683.53 km) |
| Upper Grand Lagoon to Olsberg | 4,791.40 mi (7,711.02 km) |
| Upper Grand Lagoon to Oranienburg | 4,935.58 mi (7,943.05 km) |
| Upper Grand Lagoon to Ortenberg | 4,841.43 mi (7,791.52 km) |
