| Alton to Nasaud | 1,170.01 mi (1,882.95 km) |
| Alton to Navodari | 1,442.15 mi (2,320.92 km) |
| Alton to Negresti-Oas | 1,112.48 mi (1,790.36 km) |
| Alton to Nehoiu | 1,308.72 mi (2,106.19 km) |
| Alton to Ocna Mures | 1,171.50 mi (1,885.34 km) |
| Alton to Odobesti | 1,328.56 mi (2,138.10 km) |
| Alton to Odorheiu Secuiesc | 1,235.89 mi (1,988.98 km) |
| Alton to Oltenita | 1,365.62 mi (2,197.75 km) |
| Alton to Onesti | 1,300.91 mi (2,093.61 km) |
| Alton to Oradea | 1,068.39 mi (1,719.41 km) |
| Alton to Orastie | 1,159.67 mi (1,866.30 km) |
| Alton to Oravita | 1,122.08 mi (1,805.81 km) |
| Alton to Orsova | 1,163.11 mi (1,871.84 km) |
| Alton to Otelu Rosu | 1,134.18 mi (1,825.29 km) |
| Alton to Otopeni | 1,325.30 mi (2,132.86 km) |
