| Mountain Ash to Oberkirch | 551.78 mi (888.01 km) |
| Mountain Ash to Obernburg am Main | 561.05 mi (902.93 km) |
| Mountain Ash to Obernkirchen | 532.77 mi (857.42 km) |
| Mountain Ash to Oberschleissheim | 703.76 mi (1,132.60 km) |
| Mountain Ash to Oberstdorf | 678.32 mi (1,091.66 km) |
| Mountain Ash to Obertraubling | 709.45 mi (1,141.75 km) |
| Mountain Ash to Obertshausen | 543.33 mi (874.41 km) |
| Mountain Ash to Oberursel | 529.80 mi (852.64 km) |
| Mountain Ash to Ochsenfurt | 604.40 mi (972.69 km) |
| Mountain Ash to Ochsenhausen | 642.48 mi (1,033.98 km) |
| Mountain Ash to Ochtrup | 451.22 mi (726.17 km) |
| Mountain Ash to Odenthal | 454.67 mi (731.72 km) |
| Mountain Ash to Oelde | 492.68 mi (792.89 km) |
| Mountain Ash to Oelsnitz | 679.56 mi (1,093.64 km) |
| Mountain Ash to Oer-Erkenschwick | 455.19 mi (732.56 km) |
