| Slough to Nasaud | 1,155.00 mi (1,858.79 km) |
| Slough to Navodari | 1,429.03 mi (2,299.81 km) |
| Slough to Negresti-Oas | 1,097.00 mi (1,765.45 km) |
| Slough to Nehoiu | 1,295.47 mi (2,084.85 km) |
| Slough to Ocna Mures | 1,158.02 mi (1,863.65 km) |
| Slough to Odobesti | 1,314.42 mi (2,115.36 km) |
| Slough to Odorheiu Secuiesc | 1,221.84 mi (1,966.36 km) |
| Slough to Oltenita | 1,353.77 mi (2,178.69 km) |
| Slough to Onesti | 1,286.28 mi (2,070.06 km) |
| Slough to Oradea | 1,054.83 mi (1,697.58 km) |
| Slough to Orastie | 1,147.31 mi (1,846.42 km) |
| Slough to Oravita | 1,111.82 mi (1,789.30 km) |
| Slough to Orsova | 1,152.86 mi (1,855.36 km) |
| Slough to Otelu Rosu | 1,122.79 mi (1,806.96 km) |
| Slough to Otopeni | 1,313.18 mi (2,113.35 km) |
