| Castalla to Olympia Heights (Florida) | 4,602.04 mi (7,406.27 km) |
| Castalla to Omaha (Nebraska) | 4,776.11 mi (7,686.41 km) |
| Castalla to On Top of the World Designated Place (Florida) | 4,576.26 mi (7,364.79 km) |
| Castalla to Onalaska (Wisconsin) | 4,471.03 mi (7,195.42 km) |
| Castalla to Oneida (New York) | 3,798.55 mi (6,113.18 km) |
| Castalla to Oneonta (New York) | 3,787.41 mi (6,095.25 km) |
| Castalla to Ontario (California) | 5,997.28 mi (9,651.70 km) |
| Castalla to Ontario (Oregon) | 5,483.71 mi (8,825.18 km) |
| Castalla to Opa-locka (Florida) | 4,591.06 mi (7,388.59 km) |
| Castalla to Opelika (Alabama) | 4,600.64 mi (7,404.02 km) |
| Castalla to Opelousas (Louisiana) | 5,011.03 mi (8,064.47 km) |
| Castalla to Orange (California) | 6,017.56 mi (9,684.33 km) |
| Castalla to Orange (Texas) | 5,108.80 mi (8,221.82 km) |
| Castalla to Orange City (Florida) | 4,531.54 mi (7,292.81 km) |
| Castalla to Orangeburg (South Carolina) | 4,347.36 mi (6,996.39 km) |
