| Harpenden to Cividale del Friuli | 737.91 mi (1,187.56 km) |
| Harpenden to Civita Castellana | 888.35 mi (1,429.66 km) |
| Harpenden to Civitanova Marche | 879.12 mi (1,414.80 km) |
| Harpenden to Civitavecchia | 880.38 mi (1,416.83 km) |
| Harpenden to Civitella in Val di Chiana | 806.00 mi (1,297.13 km) |
| Harpenden to Clusone | 621.46 mi (1,000.14 km) |
| Harpenden to Coccaglio | 638.23 mi (1,027.12 km) |
| Harpenden to Codigoro | 747.22 mi (1,202.53 km) |
| Harpenden to Codogno | 649.80 mi (1,045.76 km) |
| Harpenden to Codroipo | 726.60 mi (1,169.34 km) |
| Harpenden to Cogoleto | 659.13 mi (1,060.76 km) |
| Harpenden to Colle di Val d'Elsa | 788.42 mi (1,268.84 km) |
| Harpenden to Colle Salvetti | 757.45 mi (1,219.00 km) |
| Harpenden to Collecchio | 687.60 mi (1,106.58 km) |
| Harpenden to Colleferro | 938.16 mi (1,509.83 km) |
