| Seclin to Navodari | 1,263.13 mi (2,032.80 km) |
| Seclin to Negresti-Oas | 935.86 mi (1,506.13 km) |
| Seclin to Nehoiu | 1,129.81 mi (1,818.25 km) |
| Seclin to Ocna Mures | 992.77 mi (1,597.71 km) |
| Seclin to Odobesti | 1,150.30 mi (1,851.23 km) |
| Seclin to Odorheiu Secuiesc | 1,057.60 mi (1,702.05 km) |
| Seclin to Oltenita | 1,186.10 mi (1,908.84 km) |
| Seclin to Onesti | 1,123.14 mi (1,807.52 km) |
| Seclin to Oradea | 889.77 mi (1,431.95 km) |
| Seclin to Orastie | 980.32 mi (1,577.67 km) |
| Seclin to Oravita | 942.53 mi (1,516.85 km) |
| Seclin to Orsova | 983.56 mi (1,582.89 km) |
| Seclin to Otelu Rosu | 954.59 mi (1,536.27 km) |
| Seclin to Otopeni | 1,145.85 mi (1,844.07 km) |
| Seclin to Ovidiu | 1,262.54 mi (2,031.86 km) |
