| Seini to Mangualde | 1,603.23 mi (2,580.15 km) |
| Seini to Marco de Canavezes | 1,602.61 mi (2,579.15 km) |
| Seini to Marinha Grande | 1,686.00 mi (2,713.35 km) |
| Seini to Massama | 1,736.74 mi (2,795.01 km) |
| Seini to Matosinhos | 1,628.08 mi (2,620.14 km) |
| Seini to Mealhada | 1,642.33 mi (2,643.07 km) |
| Seini to Melgaco | 1,579.65 mi (2,542.21 km) |
| Seini to Melres | 1,617.86 mi (2,603.70 km) |
| Seini to Mira | 1,653.76 mi (2,661.47 km) |
| Seini to Miranda do Corvo | 1,646.42 mi (2,649.65 km) |
| Seini to Mirandela | 1,548.36 mi (2,491.85 km) |
| Seini to Mogadouro | 1,531.59 mi (2,464.85 km) |
| Seini to Moimenta da Beira | 1,584.25 mi (2,549.61 km) |
| Seini to Moita | 1,727.25 mi (2,779.74 km) |
| Seini to Moncao | 1,590.83 mi (2,560.19 km) |
