| Greenbelt to Mangualde | 3,572.15 mi (5,748.81 km) |
| Greenbelt to Marco de Canavezes | 3,538.33 mi (5,694.40 km) |
| Greenbelt to Marinha Grande | 3,537.35 mi (5,692.82 km) |
| Greenbelt to Massama | 3,547.01 mi (5,708.36 km) |
| Greenbelt to Matosinhos | 3,511.74 mi (5,651.59 km) |
| Greenbelt to Mealhada | 3,544.41 mi (5,704.17 km) |
| Greenbelt to Melgaco | 3,509.29 mi (5,647.65 km) |
| Greenbelt to Melres | 3,529.22 mi (5,679.73 km) |
| Greenbelt to Mira | 3,529.30 mi (5,679.85 km) |
| Greenbelt to Miranda do Corvo | 3,557.52 mi (5,725.28 km) |
| Greenbelt to Mirandela | 3,577.24 mi (5,757.01 km) |
| Greenbelt to Mogadouro | 3,603.51 mi (5,799.30 km) |
| Greenbelt to Moimenta da Beira | 3,569.50 mi (5,744.55 km) |
| Greenbelt to Moita | 3,564.36 mi (5,736.29 km) |
| Greenbelt to Moncao | 3,500.14 mi (5,632.93 km) |
