| Harpenden to Islahiye | 2,060.73 mi (3,316.43 km) |
| Harpenden to Isparta | 1,779.40 mi (2,863.66 km) |
| Harpenden to Istanbul | 1,568.06 mi (2,523.55 km) |
| Harpenden to Izmir | 1,613.41 mi (2,596.53 km) |
| Harpenden to Kadinhani | 1,823.96 mi (2,935.38 km) |
| Harpenden to Kadirli | 2,022.92 mi (3,255.57 km) |
| Harpenden to Kagithane | 1,566.03 mi (2,520.28 km) |
| Harpenden to Kahramanmaras | 2,047.69 mi (3,295.43 km) |
| Harpenden to Kahta | 2,109.17 mi (3,394.38 km) |
| Harpenden to Kaman | 1,835.92 mi (2,954.63 km) |
| Harpenden to Kangal | 1,993.89 mi (3,208.86 km) |
| Harpenden to Kapakli | 1,514.03 mi (2,436.59 km) |
| Harpenden to Karaagac | 2,061.30 mi (3,317.34 km) |
| Harpenden to Karaagac | 1,514.77 mi (2,437.79 km) |
| Harpenden to Karabuk | 1,712.08 mi (2,755.33 km) |
