| Cave Spring to Mangualde | 3,778.41 mi (6,080.76 km) |
| Cave Spring to Marco de Canavezes | 3,744.90 mi (6,026.84 km) |
| Cave Spring to Marinha Grande | 3,742.72 mi (6,023.32 km) |
| Cave Spring to Massama | 3,751.45 mi (6,037.38 km) |
| Cave Spring to Matosinhos | 3,718.20 mi (5,983.86 km) |
| Cave Spring to Mealhada | 3,750.36 mi (6,035.63 km) |
| Cave Spring to Melgaco | 3,716.41 mi (5,980.99 km) |
| Cave Spring to Melres | 3,735.66 mi (6,011.97 km) |
| Cave Spring to Mira | 3,735.23 mi (6,011.27 km) |
| Cave Spring to Miranda do Corvo | 3,763.30 mi (6,056.44 km) |
| Cave Spring to Mirandela | 3,784.18 mi (6,090.04 km) |
| Cave Spring to Mogadouro | 3,810.44 mi (6,132.32 km) |
| Cave Spring to Moimenta da Beira | 3,776.04 mi (6,076.95 km) |
| Cave Spring to Moita | 3,768.79 mi (6,065.29 km) |
| Cave Spring to Moncao | 3,707.20 mi (5,966.17 km) |
