| Mason City to Mangualde | 4,195.02 mi (6,751.23 km) |
| Mason City to Marco de Canavezes | 4,156.08 mi (6,688.56 km) |
| Mason City to Marinha Grande | 4,175.94 mi (6,720.53 km) |
| Mason City to Massama | 4,198.69 mi (6,757.14 km) |
| Mason City to Matosinhos | 4,132.08 mi (6,649.94 km) |
| Mason City to Mealhada | 4,173.21 mi (6,716.13 km) |
| Mason City to Melgaco | 4,116.06 mi (6,624.17 km) |
| Mason City to Melres | 4,149.56 mi (6,678.08 km) |
| Mason City to Mira | 4,158.85 mi (6,693.02 km) |
| Mason City to Miranda do Corvo | 4,189.13 mi (6,741.75 km) |
| Mason City to Mirandela | 4,186.69 mi (6,737.82 km) |
| Mason City to Mogadouro | 4,212.58 mi (6,779.49 km) |
| Mason City to Moimenta da Beira | 4,187.16 mi (6,738.58 km) |
| Mason City to Moita | 4,215.86 mi (6,784.77 km) |
| Mason City to Moncao | 4,108.46 mi (6,611.92 km) |
