| Castro Daire to Oerlinghausen | 1,094.91 mi (1,762.08 km) |
| Castro Daire to Oestrich-Winkel | 992.31 mi (1,596.97 km) |
| Castro Daire to Offenburg | 935.67 mi (1,505.82 km) |
| Castro Daire to Oftersheim | 991.82 mi (1,596.17 km) |
| Castro Daire to Ohrdruf | 1,124.72 mi (1,810.06 km) |
| Castro Daire to Ohringen | 1,022.33 mi (1,645.28 km) |
| Castro Daire to Olbernhau | 1,220.07 mi (1,963.51 km) |
| Castro Daire to Olching | 1,069.52 mi (1,721.23 km) |
| Castro Daire to Oldenburg | 1,132.36 mi (1,822.36 km) |
| Castro Daire to Oldenburg in Holstein | 1,267.21 mi (2,039.37 km) |
| Castro Daire to Olfen | 1,041.38 mi (1,675.94 km) |
| Castro Daire to Olpe | 1,026.62 mi (1,652.19 km) |
| Castro Daire to Olsberg | 1,062.95 mi (1,710.66 km) |
| Castro Daire to Oranienburg | 1,284.75 mi (2,067.61 km) |
| Castro Daire to Ortenberg | 1,044.89 mi (1,681.58 km) |
