| Giessen to Navodari | 1,023.22 mi (1,646.72 km) |
| Giessen to Negresti-Oas | 690.48 mi (1,111.22 km) |
| Giessen to Nehoiu | 889.56 mi (1,431.60 km) |
| Giessen to Ocna Mures | 751.93 mi (1,210.12 km) |
| Giessen to Odobesti | 907.77 mi (1,460.92 km) |
| Giessen to Odorheiu Secuiesc | 815.25 mi (1,312.02 km) |
| Giessen to Oltenita | 950.23 mi (1,529.25 km) |
| Giessen to Onesti | 879.50 mi (1,415.42 km) |
| Giessen to Oradea | 648.73 mi (1,044.02 km) |
| Giessen to Orastie | 743.02 mi (1,195.78 km) |
| Giessen to Oravita | 713.72 mi (1,148.62 km) |
| Giessen to Orsova | 754.60 mi (1,214.40 km) |
| Giessen to Otelu Rosu | 720.94 mi (1,160.23 km) |
| Giessen to Otopeni | 909.11 mi (1,463.07 km) |
| Giessen to Ovidiu | 1,022.87 mi (1,646.15 km) |
