| Whitburn to Mangualde | 1,070.29 mi (1,722.47 km) |
| Whitburn to Marco de Canavezes | 1,034.02 mi (1,664.10 km) |
| Whitburn to Marinha Grande | 1,138.74 mi (1,832.62 km) |
| Whitburn to Massama | 1,209.53 mi (1,946.56 km) |
| Whitburn to Matosinhos | 1,039.14 mi (1,672.34 km) |
| Whitburn to Mealhada | 1,091.16 mi (1,756.06 km) |
| Whitburn to Melgaco | 971.61 mi (1,563.65 km) |
| Whitburn to Melres | 1,044.21 mi (1,680.49 km) |
| Whitburn to Mira | 1,090.39 mi (1,754.81 km) |
| Whitburn to Miranda do Corvo | 1,109.43 mi (1,785.45 km) |
| Whitburn to Mirandela | 1,005.73 mi (1,618.56 km) |
| Whitburn to Mogadouro | 1,013.09 mi (1,630.42 km) |
| Whitburn to Moimenta da Beira | 1,043.49 mi (1,679.34 km) |
| Whitburn to Moita | 1,214.02 mi (1,953.78 km) |
| Whitburn to Moncao | 976.61 mi (1,571.71 km) |
