| Harpenden to Cernavoda | 1,397.53 mi (2,249.11 km) |
| Harpenden to Chitila | 1,305.40 mi (2,100.83 km) |
| Harpenden to Cisnadie | 1,186.04 mi (1,908.74 km) |
| Harpenden to Cluj-Napoca | 1,127.66 mi (1,814.80 km) |
| Harpenden to Codlea | 1,240.90 mi (1,997.04 km) |
| Harpenden to Comanesti | 1,259.57 mi (2,027.09 km) |
| Harpenden to Comarnic | 1,264.26 mi (2,034.63 km) |
| Harpenden to Constanta | 1,428.99 mi (2,299.73 km) |
| Harpenden to Corabia | 1,272.10 mi (2,047.24 km) |
| Harpenden to Costesti | 1,253.56 mi (2,017.41 km) |
| Harpenden to Covasna | 1,267.08 mi (2,039.17 km) |
| Harpenden to Craiova | 1,222.18 mi (1,966.91 km) |
| Harpenden to Cristuru Secuiesc | 1,204.05 mi (1,937.73 km) |
| Harpenden to Cugir | 1,148.60 mi (1,848.50 km) |
| Harpenden to Cumpana | 1,427.71 mi (2,297.67 km) |
