| Gladbeck to Navodari | 1,114.22 mi (1,793.16 km) |
| Gladbeck to Negresti-Oas | 776.29 mi (1,249.32 km) |
| Gladbeck to Nehoiu | 980.57 mi (1,578.08 km) |
| Gladbeck to Ocna Mures | 842.87 mi (1,356.47 km) |
| Gladbeck to Odobesti | 996.73 mi (1,604.08 km) |
| Gladbeck to Odorheiu Secuiesc | 904.63 mi (1,455.86 km) |
| Gladbeck to Oltenita | 1,043.86 mi (1,679.93 km) |
| Gladbeck to Onesti | 967.28 mi (1,556.69 km) |
| Gladbeck to Oradea | 739.86 mi (1,190.69 km) |
| Gladbeck to Orastie | 836.38 mi (1,346.02 km) |
| Gladbeck to Oravita | 810.66 mi (1,304.63 km) |
| Gladbeck to Orsova | 851.39 mi (1,370.18 km) |
| Gladbeck to Otelu Rosu | 816.14 mi (1,313.46 km) |
| Gladbeck to Otopeni | 1,002.36 mi (1,613.14 km) |
| Gladbeck to Ovidiu | 1,114.04 mi (1,792.88 km) |
