| Greenbelt to Oberkirch | 4,069.13 mi (6,548.63 km) |
| Greenbelt to Obernburg am Main | 4,073.86 mi (6,556.25 km) |
| Greenbelt to Obernkirchen | 4,003.38 mi (6,442.81 km) |
| Greenbelt to Oberschleissheim | 4,221.01 mi (6,793.06 km) |
| Greenbelt to Oberstdorf | 4,194.54 mi (6,750.46 km) |
| Greenbelt to Obertraubling | 4,222.56 mi (6,795.55 km) |
| Greenbelt to Obertshausen | 4,054.82 mi (6,525.61 km) |
| Greenbelt to Oberursel | 4,040.56 mi (6,502.65 km) |
| Greenbelt to Ochsenfurt | 4,116.80 mi (6,625.35 km) |
| Greenbelt to Ochsenhausen | 4,160.13 mi (6,695.09 km) |
| Greenbelt to Ochtrup | 3,930.08 mi (6,324.86 km) |
| Greenbelt to Odenthal | 3,958.77 mi (6,371.02 km) |
| Greenbelt to Oelde | 3,977.70 mi (6,401.49 km) |
| Greenbelt to Oelsnitz | 4,176.92 mi (6,722.10 km) |
| Greenbelt to Oer-Erkenschwick | 3,947.56 mi (6,352.98 km) |
