| Alpena to Oberkirch | 4,062.28 mi (6,537.61 km) |
| Alpena to Obernburg am Main | 4,050.83 mi (6,519.17 km) |
| Alpena to Obernkirchen | 3,957.08 mi (6,368.30 km) |
| Alpena to Oberschleissheim | 4,203.94 mi (6,765.59 km) |
| Alpena to Oberstdorf | 4,190.03 mi (6,743.20 km) |
| Alpena to Obertraubling | 4,196.73 mi (6,753.98 km) |
| Alpena to Obertshausen | 4,030.70 mi (6,486.78 km) |
| Alpena to Oberursel | 4,016.01 mi (6,463.14 km) |
| Alpena to Ochsenfurt | 4,092.29 mi (6,585.90 km) |
| Alpena to Ochsenhausen | 4,150.77 mi (6,680.02 km) |
| Alpena to Ochtrup | 3,890.52 mi (6,261.19 km) |
| Alpena to Odenthal | 3,931.06 mi (6,326.42 km) |
| Alpena to Oelde | 3,938.76 mi (6,338.82 km) |
| Alpena to Oelsnitz | 4,137.80 mi (6,659.15 km) |
| Alpena to Oer-Erkenschwick | 3,913.39 mi (6,298.00 km) |
