| Key Largo to Mangualde | 4,230.60 mi (6,808.49 km) |
| Key Largo to Marco de Canavezes | 4,204.05 mi (6,765.77 km) |
| Key Largo to Marinha Grande | 4,179.34 mi (6,726.00 km) |
| Key Largo to Massama | 4,172.78 mi (6,715.43 km) |
| Key Largo to Matosinhos | 4,175.80 mi (6,720.30 km) |
| Key Largo to Mealhada | 4,197.41 mi (6,755.09 km) |
| Key Largo to Melgaco | 4,188.24 mi (6,740.33 km) |
| Key Largo to Melres | 4,192.47 mi (6,747.13 km) |
| Key Largo to Mira | 4,182.15 mi (6,730.52 km) |
| Key Largo to Miranda do Corvo | 4,206.70 mi (6,770.04 km) |
| Key Largo to Mirandela | 4,250.26 mi (6,840.14 km) |
| Key Largo to Mogadouro | 4,275.78 mi (6,881.20 km) |
| Key Largo to Moimenta da Beira | 4,233.90 mi (6,813.80 km) |
| Key Largo to Moita | 4,189.53 mi (6,742.39 km) |
| Key Largo to Moncao | 4,177.87 mi (6,723.63 km) |
