| Castelfidardo to Oegstgeest | 733.85 mi (1,181.01 km) |
| Castelfidardo to Oirschot | 674.75 mi (1,085.90 km) |
| Castelfidardo to Oisterwijk | 681.93 mi (1,097.45 km) |
| Castelfidardo to Oldebroek | 713.67 mi (1,148.54 km) |
| Castelfidardo to Oldenzaal | 683.41 mi (1,099.84 km) |
| Castelfidardo to Ommen | 706.22 mi (1,136.56 km) |
| Castelfidardo to Oosterend | 742.65 mi (1,195.17 km) |
| Castelfidardo to Oosterhout | 694.31 mi (1,117.39 km) |
| Castelfidardo to Oosterwolde | 737.16 mi (1,186.35 km) |
| Castelfidardo to Oostzaan | 736.92 mi (1,185.95 km) |
| Castelfidardo to Opmeer | 750.25 mi (1,207.41 km) |
| Castelfidardo to Oss | 683.87 mi (1,100.58 km) |
| Castelfidardo to Oud-Beijerland | 715.99 mi (1,152.28 km) |
| Castelfidardo to Oudenbosch | 700.55 mi (1,127.43 km) |
| Castelfidardo to Oudewater | 714.32 mi (1,149.59 km) |
