| Harpenden to Carpentras | 591.30 mi (951.60 km) |
| Harpenden to Carquefou | 316.49 mi (509.34 km) |
| Harpenden to Carqueiranne | 672.67 mi (1,082.56 km) |
| Harpenden to Carrieres-sous-Poissy | 224.49 mi (361.29 km) |
| Harpenden to Carrieres-sur-Seine | 232.10 mi (373.53 km) |
| Harpenden to Carros | 656.21 mi (1,056.06 km) |
| Harpenden to Carvin | 170.14 mi (273.81 km) |
| Harpenden to Castanet-Tolosan | 579.98 mi (933.39 km) |
| Harpenden to Castelginest | 567.35 mi (913.06 km) |
| Harpenden to Castelnau-le-Lez | 598.55 mi (963.27 km) |
| Harpenden to Castelnaudary | 596.93 mi (960.67 km) |
| Harpenden to Castelsarrasin | 541.57 mi (871.58 km) |
| Harpenden to Castres | 580.42 mi (934.10 km) |
| Harpenden to Caudebec-les-Elbeuf | 185.34 mi (298.28 km) |
| Harpenden to Caudry | 201.20 mi (323.79 km) |
