| Gretna to Olivares | 4,691.89 mi (7,550.87 km) |
| Gretna to Olivenza | 4,612.12 mi (7,422.48 km) |
| Gretna to Olot | 4,985.77 mi (8,023.82 km) |
| Gretna to Onate | 4,733.19 mi (7,617.33 km) |
| Gretna to Onda | 4,917.49 mi (7,913.93 km) |
| Gretna to Onteniente | 4,932.46 mi (7,938.03 km) |
| Gretna to Orihuela | 4,936.26 mi (7,944.14 km) |
| Gretna to Osuna | 4,750.16 mi (7,644.64 km) |
| Gretna to Ourense | 4,489.76 mi (7,225.58 km) |
| Gretna to Oviedo | 4,563.47 mi (7,344.19 km) |
| Gretna to Paiporta | 4,924.84 mi (7,925.76 km) |
| Gretna to Pajara | 4,493.95 mi (7,232.31 km) |
| Gretna to Palafolls | 5,012.79 mi (8,067.30 km) |
| Gretna to Palafrugell | 5,024.84 mi (8,086.69 km) |
| Gretna to Palamos | 5,025.33 mi (8,087.49 km) |
