| Glenn Dale to Mangualde | 3,568.40 mi (5,742.78 km) |
| Glenn Dale to Marco de Canavezes | 3,534.61 mi (5,688.41 km) |
| Glenn Dale to Marinha Grande | 3,533.54 mi (5,686.68 km) |
| Glenn Dale to Massama | 3,543.14 mi (5,702.13 km) |
| Glenn Dale to Matosinhos | 3,508.00 mi (5,645.59 km) |
| Glenn Dale to Mealhada | 3,540.63 mi (5,698.10 km) |
| Glenn Dale to Melgaco | 3,505.62 mi (5,641.74 km) |
| Glenn Dale to Melres | 3,525.48 mi (5,673.72 km) |
| Glenn Dale to Mira | 3,525.52 mi (5,673.78 km) |
| Glenn Dale to Miranda do Corvo | 3,553.74 mi (5,719.19 km) |
| Glenn Dale to Mirandela | 3,573.55 mi (5,751.07 km) |
| Glenn Dale to Mogadouro | 3,599.83 mi (5,793.36 km) |
| Glenn Dale to Moimenta da Beira | 3,565.77 mi (5,738.56 km) |
| Glenn Dale to Moita | 3,560.49 mi (5,730.06 km) |
| Glenn Dale to Moncao | 3,496.46 mi (5,627.01 km) |
