| Merthyr Tudful to Hoyo de Manzanares | 767.98 mi (1,235.95 km) |
| Merthyr Tudful to Huelva | 1,016.41 mi (1,635.75 km) |
| Merthyr Tudful to Huercal de Almeria | 1,027.74 mi (1,653.99 km) |
| Merthyr Tudful to Huercal-Overa | 994.65 mi (1,600.74 km) |
| Merthyr Tudful to Huesca | 678.35 mi (1,091.70 km) |
| Merthyr Tudful to Huetor Vega | 1,008.32 mi (1,622.74 km) |
| Merthyr Tudful to Huetor-Tajar | 1,005.72 mi (1,618.55 km) |
| Merthyr Tudful to Humanes de Madrid | 794.11 mi (1,278.00 km) |
| Merthyr Tudful to Ibi | 916.25 mi (1,474.57 km) |
| Merthyr Tudful to Ibiza | 916.51 mi (1,474.98 km) |
| Merthyr Tudful to Icod de los Vinos | 1,756.78 mi (2,827.26 km) |
| Merthyr Tudful to Igualada | 740.58 mi (1,191.85 km) |
| Merthyr Tudful to Illescas | 803.59 mi (1,293.26 km) |
| Merthyr Tudful to Inca | 883.84 mi (1,422.40 km) |
| Merthyr Tudful to Ingenio | 1,760.42 mi (2,833.13 km) |
