| Tulcea to Oberkirch | 1,002.24 mi (1,612.95 km) |
| Tulcea to Obernburg am Main | 968.60 mi (1,558.81 km) |
| Tulcea to Obernkirchen | 1,016.98 mi (1,636.67 km) |
| Tulcea to Oberschleissheim | 841.24 mi (1,353.85 km) |
| Tulcea to Oberstdorf | 895.08 mi (1,440.49 km) |
| Tulcea to Obertraubling | 822.97 mi (1,324.44 km) |
| Tulcea to Obertshausen | 985.27 mi (1,585.64 km) |
| Tulcea to Oberursel | 998.39 mi (1,606.75 km) |
| Tulcea to Ochsenfurt | 925.46 mi (1,489.38 km) |
| Tulcea to Ochsenhausen | 913.85 mi (1,470.70 km) |
| Tulcea to Ochtrup | 1,092.56 mi (1,758.31 km) |
| Tulcea to Odenthal | 1,073.71 mi (1,727.98 km) |
| Tulcea to Oelde | 1,045.85 mi (1,683.13 km) |
| Tulcea to Oelsnitz | 849.74 mi (1,367.53 km) |
| Tulcea to Oer-Erkenschwick | 1,078.83 mi (1,736.21 km) |
