| Idanha-a-Nova to Nuth | 988.10 mi (1,590.19 km) |
| Idanha-a-Nova to Oegstgeest | 1,013.62 mi (1,631.27 km) |
| Idanha-a-Nova to Oirschot | 1,000.14 mi (1,609.56 km) |
| Idanha-a-Nova to Oisterwijk | 1,001.60 mi (1,611.92 km) |
| Idanha-a-Nova to Oldebroek | 1,066.29 mi (1,716.04 km) |
| Idanha-a-Nova to Oldenzaal | 1,088.83 mi (1,752.30 km) |
| Idanha-a-Nova to Ommen | 1,084.14 mi (1,744.76 km) |
| Idanha-a-Nova to Oosterend | 1,099.91 mi (1,770.14 km) |
| Idanha-a-Nova to Oosterhout | 995.12 mi (1,601.49 km) |
| Idanha-a-Nova to Oosterwolde | 1,105.27 mi (1,778.75 km) |
| Idanha-a-Nova to Oostzaan | 1,038.08 mi (1,670.63 km) |
| Idanha-a-Nova to Opmeer | 1,054.30 mi (1,696.73 km) |
| Idanha-a-Nova to Oss | 1,020.08 mi (1,641.66 km) |
| Idanha-a-Nova to Oud-Beijerland | 991.97 mi (1,596.43 km) |
| Idanha-a-Nova to Oudenbosch | 983.10 mi (1,582.15 km) |
