| Castel San Giorgio to Oegstgeest | 923.97 mi (1,486.98 km) |
| Castel San Giorgio to Oirschot | 864.89 mi (1,391.90 km) |
| Castel San Giorgio to Oisterwijk | 872.06 mi (1,403.45 km) |
| Castel San Giorgio to Oldebroek | 906.30 mi (1,458.56 km) |
| Castel San Giorgio to Oldenzaal | 876.99 mi (1,411.37 km) |
| Castel San Giorgio to Ommen | 899.49 mi (1,447.59 km) |
| Castel San Giorgio to Oosterend | 936.01 mi (1,506.37 km) |
| Castel San Giorgio to Oosterhout | 883.95 mi (1,422.58 km) |
| Castel San Giorgio to Oosterwolde | 930.71 mi (1,497.84 km) |
| Castel San Giorgio to Oostzaan | 928.17 mi (1,493.74 km) |
| Castel San Giorgio to Opmeer | 942.02 mi (1,516.03 km) |
| Castel San Giorgio to Oss | 874.93 mi (1,408.06 km) |
| Castel San Giorgio to Oud-Beijerland | 905.18 mi (1,456.74 km) |
| Castel San Giorgio to Oudenbosch | 889.41 mi (1,431.37 km) |
| Castel San Giorgio to Oudewater | 904.78 mi (1,456.10 km) |
