| Altena to Navodari | 1,079.82 mi (1,737.79 km) |
| Altena to Negresti-Oas | 742.85 mi (1,195.50 km) |
| Altena to Nehoiu | 946.14 mi (1,522.67 km) |
| Altena to Ocna Mures | 808.43 mi (1,301.05 km) |
| Altena to Odobesti | 962.70 mi (1,549.32 km) |
| Altena to Odorheiu Secuiesc | 870.50 mi (1,400.93 km) |
| Altena to Oltenita | 1,009.00 mi (1,623.82 km) |
| Altena to Onesti | 933.49 mi (1,502.30 km) |
| Altena to Oradea | 705.37 mi (1,135.18 km) |
| Altena to Orastie | 801.53 mi (1,289.95 km) |
| Altena to Oravita | 775.38 mi (1,247.85 km) |
| Altena to Orsova | 816.12 mi (1,313.42 km) |
| Altena to Otelu Rosu | 781.04 mi (1,256.96 km) |
| Altena to Otopeni | 967.55 mi (1,557.12 km) |
| Altena to Ovidiu | 1,079.61 mi (1,737.46 km) |
