| Castle Rock to Nuth | 4,929.35 mi (7,933.02 km) |
| Castle Rock to Oegstgeest | 4,826.65 mi (7,767.75 km) |
| Castle Rock to Oirschot | 4,884.10 mi (7,860.20 km) |
| Castle Rock to Oisterwijk | 4,877.12 mi (7,848.97 km) |
| Castle Rock to Oldebroek | 4,861.70 mi (7,824.15 km) |
| Castle Rock to Oldenzaal | 4,900.92 mi (7,887.26 km) |
| Castle Rock to Ommen | 4,875.38 mi (7,846.17 km) |
| Castle Rock to Oosterend | 4,842.53 mi (7,793.30 km) |
| Castle Rock to Oosterhout | 4,863.14 mi (7,826.46 km) |
| Castle Rock to Oosterwolde | 4,850.30 mi (7,805.80 km) |
| Castle Rock to Oostzaan | 4,829.41 mi (7,772.19 km) |
| Castle Rock to Opmeer | 4,819.94 mi (7,756.94 km) |
| Castle Rock to Oss | 4,879.46 mi (7,852.72 km) |
| Castle Rock to Oud-Beijerland | 4,840.41 mi (7,789.88 km) |
| Castle Rock to Oudenbosch | 4,854.44 mi (7,812.47 km) |
