| Harlingen to Navodari | 1,212.62 mi (1,951.52 km) |
| Harlingen to Negresti-Oas | 868.25 mi (1,397.31 km) |
| Harlingen to Nehoiu | 1,079.61 mi (1,737.46 km) |
| Harlingen to Ocna Mures | 942.57 mi (1,516.92 km) |
| Harlingen to Odobesti | 1,092.12 mi (1,757.60 km) |
| Harlingen to Odorheiu Secuiesc | 1,001.29 mi (1,611.42 km) |
| Harlingen to Oltenita | 1,147.44 mi (1,846.63 km) |
| Harlingen to Onesti | 1,060.88 mi (1,707.33 km) |
| Harlingen to Oradea | 840.67 mi (1,352.93 km) |
| Harlingen to Orastie | 940.42 mi (1,513.45 km) |
| Harlingen to Oravita | 921.94 mi (1,483.71 km) |
| Harlingen to Orsova | 962.18 mi (1,548.48 km) |
| Harlingen to Otelu Rosu | 923.79 mi (1,486.70 km) |
| Harlingen to Otopeni | 1,105.37 mi (1,778.92 km) |
| Harlingen to Ovidiu | 1,212.76 mi (1,951.75 km) |
