| Castaic to Oberkirch | 5,830.17 mi (9,382.75 km) |
| Castaic to Obernburg am Main | 5,793.83 mi (9,324.27 km) |
| Castaic to Obernkirchen | 5,666.73 mi (9,119.72 km) |
| Castaic to Oberschleissheim | 5,948.58 mi (9,573.32 km) |
| Castaic to Oberstdorf | 5,955.30 mi (9,584.13 km) |
| Castaic to Obertraubling | 5,927.34 mi (9,539.14 km) |
| Castaic to Obertshausen | 5,773.03 mi (9,290.79 km) |
| Castaic to Oberursel | 5,758.44 mi (9,267.32 km) |
| Castaic to Ochsenfurt | 5,830.69 mi (9,383.59 km) |
| Castaic to Ochsenhausen | 5,910.39 mi (9,511.85 km) |
| Castaic to Ochtrup | 5,615.44 mi (9,037.17 km) |
| Castaic to Odenthal | 5,673.01 mi (9,129.82 km) |
| Castaic to Oelde | 5,661.90 mi (9,111.95 km) |
| Castaic to Oelsnitz | 5,849.18 mi (9,413.34 km) |
| Castaic to Oer-Erkenschwick | 5,645.88 mi (9,086.17 km) |
