| Harpenden to Butzbach | 402.08 mi (647.09 km) |
| Harpenden to Buxtehude | 436.35 mi (702.23 km) |
| Harpenden to Cadolzburg | 517.54 mi (832.90 km) |
| Harpenden to Calbe | 516.95 mi (831.96 km) |
| Harpenden to Calw | 454.43 mi (731.34 km) |
| Harpenden to Castrop-Rauxel | 328.90 mi (529.31 km) |
| Harpenden to Celle | 444.80 mi (715.83 km) |
| Harpenden to Cham | 597.88 mi (962.19 km) |
| Harpenden to Chemnitz | 576.11 mi (927.17 km) |
| Harpenden to Clausthal-Zellerfeld | 456.15 mi (734.11 km) |
| Harpenden to Cloppenburg | 361.63 mi (581.99 km) |
| Harpenden to Coburg | 502.71 mi (809.04 km) |
| Harpenden to Coesfeld | 320.67 mi (516.06 km) |
| Harpenden to Cologne | 320.74 mi (516.18 km) |
| Harpenden to Coswig | 600.66 mi (966.66 km) |
