| Opwijk to Navodari | 1,219.31 mi (1,962.28 km) |
| Opwijk to Negresti-Oas | 888.11 mi (1,429.28 km) |
| Opwijk to Nehoiu | 1,085.74 mi (1,747.32 km) |
| Opwijk to Ocna Mures | 948.29 mi (1,526.12 km) |
| Opwijk to Odobesti | 1,104.81 mi (1,778.02 km) |
| Opwijk to Odorheiu Secuiesc | 1,012.20 mi (1,628.98 km) |
| Opwijk to Oltenita | 1,144.40 mi (1,841.74 km) |
| Opwijk to Onesti | 1,076.85 mi (1,733.03 km) |
| Opwijk to Oradea | 845.10 mi (1,360.06 km) |
| Opwijk to Orastie | 937.75 mi (1,509.17 km) |
| Opwijk to Oravita | 903.75 mi (1,454.44 km) |
| Opwijk to Orsova | 944.78 mi (1,520.48 km) |
| Opwijk to Otelu Rosu | 913.74 mi (1,470.52 km) |
| Opwijk to Otopeni | 1,103.69 mi (1,776.22 km) |
| Opwijk to Ovidiu | 1,218.86 mi (1,961.56 km) |
