| Cwmbran to Mangualde | 795.99 mi (1,281.02 km) |
| Cwmbran to Marco de Canavezes | 763.04 mi (1,228.00 km) |
| Cwmbran to Marinha Grande | 869.78 mi (1,399.77 km) |
| Cwmbran to Massama | 940.75 mi (1,513.99 km) |
| Cwmbran to Matosinhos | 771.72 mi (1,241.96 km) |
| Cwmbran to Mealhada | 820.50 mi (1,320.46 km) |
| Cwmbran to Melgaco | 703.46 mi (1,132.11 km) |
| Cwmbran to Melres | 774.57 mi (1,246.55 km) |
| Cwmbran to Mira | 821.55 mi (1,322.16 km) |
| Cwmbran to Miranda do Corvo | 837.57 mi (1,347.94 km) |
| Cwmbran to Mirandela | 729.48 mi (1,173.98 km) |
| Cwmbran to Mogadouro | 734.12 mi (1,181.46 km) |
| Cwmbran to Moimenta da Beira | 768.93 mi (1,237.48 km) |
| Cwmbran to Moita | 943.43 mi (1,518.30 km) |
| Cwmbran to Moncao | 709.86 mi (1,142.41 km) |
