| Castricum to Oakley (California) | 5,402.80 mi (8,694.96 km) |
| Castricum to Oakton (Virginia) | 3,843.64 mi (6,185.75 km) |
| Castricum to Oakville (Missouri) | 4,360.63 mi (7,017.76 km) |
| Castricum to Oatfield (Oregon) | 4,983.33 mi (8,019.90 km) |
| Castricum to Ocala (Florida) | 4,517.71 mi (7,270.55 km) |
| Castricum to Ocean Acres (New Jersey) | 3,684.76 mi (5,930.04 km) |
| Castricum to Ocean City (New Jersey) | 3,719.47 mi (5,985.91 km) |
| Castricum to Ocean Pines (Maryland) | 3,782.41 mi (6,087.21 km) |
| Castricum to Ocean Pointe (Hawaii) | 7,227.98 mi (11,632.31 km) |
| Castricum to Ocean Springs (Mississippi) | 4,716.94 mi (7,591.19 km) |
| Castricum to Oceanside (California) | 5,559.70 mi (8,947.47 km) |
| Castricum to Oceanside (New York) | 3,618.52 mi (5,823.45 km) |
| Castricum to Ocoee (Florida) | 4,523.55 mi (7,279.95 km) |
| Castricum to Oconomowoc (Wisconsin) | 4,063.04 mi (6,538.84 km) |
| Castricum to Odenton (Maryland) | 3,811.42 mi (6,133.88 km) |
