| Niagara Falls to Mangualde | 3,556.80 mi (5,724.12 km) |
| Niagara Falls to Marco de Canavezes | 3,520.26 mi (5,665.31 km) |
| Niagara Falls to Marinha Grande | 3,529.84 mi (5,680.73 km) |
| Niagara Falls to Massama | 3,546.37 mi (5,707.33 km) |
| Niagara Falls to Matosinhos | 3,494.83 mi (5,624.39 km) |
| Niagara Falls to Mealhada | 3,531.92 mi (5,684.08 km) |
| Niagara Falls to Melgaco | 3,485.65 mi (5,609.60 km) |
| Niagara Falls to Melres | 3,512.40 mi (5,652.66 km) |
| Niagara Falls to Mira | 3,517.12 mi (5,660.26 km) |
| Niagara Falls to Miranda do Corvo | 3,546.52 mi (5,707.58 km) |
| Niagara Falls to Mirandela | 3,555.25 mi (5,721.63 km) |
| Niagara Falls to Mogadouro | 3,581.47 mi (5,763.82 km) |
| Niagara Falls to Moimenta da Beira | 3,551.54 mi (5,715.65 km) |
| Niagara Falls to Moita | 3,563.70 mi (5,735.22 km) |
| Niagara Falls to Moncao | 3,477.21 mi (5,596.02 km) |
