| Alton to Mangualde | 797.54 mi (1,283.52 km) |
| Alton to Marco de Canavezes | 768.55 mi (1,236.86 km) |
| Alton to Marinha Grande | 875.78 mi (1,409.43 km) |
| Alton to Massama | 946.10 mi (1,522.61 km) |
| Alton to Matosinhos | 780.51 mi (1,256.11 km) |
| Alton to Mealhada | 825.49 mi (1,328.49 km) |
| Alton to Melgaco | 712.73 mi (1,147.03 km) |
| Alton to Melres | 781.23 mi (1,257.26 km) |
| Alton to Mira | 828.30 mi (1,333.01 km) |
| Alton to Miranda do Corvo | 841.15 mi (1,353.69 km) |
| Alton to Mirandela | 729.81 mi (1,174.52 km) |
| Alton to Mogadouro | 731.05 mi (1,176.52 km) |
| Alton to Moimenta da Beira | 770.59 mi (1,240.15 km) |
| Alton to Moita | 947.04 mi (1,524.11 km) |
| Alton to Moncao | 720.32 mi (1,159.24 km) |
