| Boulder to Nasaud | 5,658.46 mi (9,106.41 km) |
| Boulder to Navodari | 5,942.31 mi (9,563.22 km) |
| Boulder to Negresti-Oas | 5,598.58 mi (9,010.05 km) |
| Boulder to Nehoiu | 5,819.60 mi (9,365.74 km) |
| Boulder to Ocna Mures | 5,692.52 mi (9,161.22 km) |
| Boulder to Odobesti | 5,817.27 mi (9,361.99 km) |
| Boulder to Odorheiu Secuiesc | 5,737.51 mi (9,233.63 km) |
| Boulder to Oltenita | 5,900.60 mi (9,496.10 km) |
| Boulder to Onesti | 5,781.21 mi (9,303.96 km) |
| Boulder to Oradea | 5,599.24 mi (9,011.10 km) |
| Boulder to Orastie | 5,703.27 mi (9,178.53 km) |
| Boulder to Oravita | 5,702.69 mi (9,177.58 km) |
| Boulder to Orsova | 5,741.23 mi (9,239.62 km) |
| Boulder to Otelu Rosu | 5,696.56 mi (9,167.73 km) |
| Boulder to Otopeni | 5,858.31 mi (9,428.03 km) |
