| Harpenden to Devnya | 1,420.39 mi (2,285.89 km) |
| Harpenden to Dimitrovgrad | 1,387.38 mi (2,232.78 km) |
| Harpenden to Dobrich | 1,417.94 mi (2,281.95 km) |
| Harpenden to Dospat | 1,347.31 mi (2,168.28 km) |
| Harpenden to Dupnitsa | 1,278.72 mi (2,057.90 km) |
| Harpenden to Elhovo | 1,421.72 mi (2,288.03 km) |
| Harpenden to Etropole | 1,289.73 mi (2,075.62 km) |
| Harpenden to Gabrovo | 1,342.45 mi (2,160.46 km) |
| Harpenden to Gorna Oryahovitsa | 1,346.64 mi (2,167.21 km) |
| Harpenden to Gotse Delchev | 1,333.86 mi (2,146.64 km) |
| Harpenden to Harmanli | 1,404.49 mi (2,260.30 km) |
| Harpenden to Haskovo | 1,391.02 mi (2,238.63 km) |
| Harpenden to Ihtiman | 1,299.09 mi (2,090.68 km) |
| Harpenden to Isperih | 1,370.57 mi (2,205.72 km) |
| Harpenden to Kardzhali | 1,395.19 mi (2,245.35 km) |
