| Niagara Falls to Hoyo de Manzanares | 3,734.40 mi (6,009.93 km) |
| Niagara Falls to Huelva | 3,707.80 mi (5,967.13 km) |
| Niagara Falls to Huercal de Almeria | 3,933.87 mi (6,330.95 km) |
| Niagara Falls to Huercal-Overa | 3,938.93 mi (6,339.09 km) |
| Niagara Falls to Huesca | 3,839.65 mi (6,179.31 km) |
| Niagara Falls to Huetor Vega | 3,871.02 mi (6,229.80 km) |
| Niagara Falls to Huetor-Tajar | 3,846.87 mi (6,190.95 km) |
| Niagara Falls to Humanes de Madrid | 3,749.83 mi (6,034.76 km) |
| Niagara Falls to Ibi | 3,956.41 mi (6,367.23 km) |
| Niagara Falls to Ibiza | 4,037.81 mi (6,498.23 km) |
| Niagara Falls to Icod de los Vinos | 3,555.83 mi (5,722.55 km) |
| Niagara Falls to Igualada | 3,949.39 mi (6,355.92 km) |
| Niagara Falls to Illescas | 3,754.26 mi (6,041.90 km) |
| Niagara Falls to Inca | 4,074.90 mi (6,557.92 km) |
| Niagara Falls to Ingenio | 3,636.27 mi (5,852.02 km) |
