| Castro Daire to Oberkirch | 943.89 mi (1,519.05 km) |
| Castro Daire to Obernburg am Main | 1,029.66 mi (1,657.07 km) |
| Castro Daire to Obernkirchen | 1,122.71 mi (1,806.83 km) |
| Castro Daire to Oberschleissheim | 1,081.51 mi (1,740.52 km) |
| Castro Daire to Oberstdorf | 1,005.33 mi (1,617.92 km) |
| Castro Daire to Obertraubling | 1,125.11 mi (1,810.69 km) |
| Castro Daire to Obertshausen | 1,025.99 mi (1,651.17 km) |
| Castro Daire to Oberursel | 1,021.41 mi (1,643.80 km) |
| Castro Daire to Ochsenfurt | 1,059.34 mi (1,704.85 km) |
| Castro Daire to Ochsenhausen | 1,007.68 mi (1,621.70 km) |
| Castro Daire to Ochtrup | 1,057.20 mi (1,701.40 km) |
| Castro Daire to Odenthal | 1,002.65 mi (1,613.61 km) |
| Castro Daire to Oelde | 1,071.88 mi (1,725.03 km) |
| Castro Daire to Oelsnitz | 1,166.45 mi (1,877.22 km) |
| Castro Daire to Oer-Erkenschwick | 1,033.72 mi (1,663.62 km) |
