| Greensboro to Mangualde | 3,806.15 mi (6,125.41 km) |
| Greensboro to Marco de Canavezes | 3,773.34 mi (6,072.60 km) |
| Greensboro to Marinha Grande | 3,768.69 mi (6,065.13 km) |
| Greensboro to Massama | 3,775.79 mi (6,076.55 km) |
| Greensboro to Matosinhos | 3,746.41 mi (6,029.26 km) |
| Greensboro to Mealhada | 3,777.49 mi (6,079.28 km) |
| Greensboro to Melgaco | 3,746.18 mi (6,028.89 km) |
| Greensboro to Melres | 3,763.82 mi (6,057.28 km) |
| Greensboro to Mira | 3,762.31 mi (6,054.85 km) |
| Greensboro to Miranda do Corvo | 3,790.06 mi (6,099.51 km) |
| Greensboro to Mirandela | 3,813.45 mi (6,137.16 km) |
| Greensboro to Mogadouro | 3,839.70 mi (6,179.39 km) |
| Greensboro to Moimenta da Beira | 3,804.40 mi (6,122.59 km) |
| Greensboro to Moita | 3,793.11 mi (6,104.42 km) |
| Greensboro to Moncao | 3,736.82 mi (6,013.84 km) |
