| Harrow to Hoyo de Manzanares | 775.09 mi (1,247.38 km) |
| Harrow to Huelva | 1,041.54 mi (1,676.19 km) |
| Harrow to Huercal de Almeria | 1,020.82 mi (1,642.85 km) |
| Harrow to Huercal-Overa | 984.20 mi (1,583.91 km) |
| Harrow to Huesca | 652.96 mi (1,050.84 km) |
| Harrow to Huetor Vega | 1,009.61 mi (1,624.81 km) |
| Harrow to Huetor-Tajar | 1,010.48 mi (1,626.21 km) |
| Harrow to Humanes de Madrid | 800.25 mi (1,287.88 km) |
| Harrow to Ibi | 895.27 mi (1,440.80 km) |
| Harrow to Ibiza | 879.93 mi (1,416.11 km) |
| Harrow to Icod de los Vinos | 1,814.53 mi (2,920.20 km) |
| Harrow to Igualada | 697.30 mi (1,122.20 km) |
| Harrow to Illescas | 809.62 mi (1,302.95 km) |
| Harrow to Inca | 834.71 mi (1,343.34 km) |
| Harrow to Ingenio | 1,812.51 mi (2,916.95 km) |
