| Sierning to Marco de Canavezes | 1,196.50 mi (1,925.58 km) |
| Sierning to Marinha Grande | 1,284.49 mi (2,067.18 km) |
| Sierning to Massama | 1,338.99 mi (2,154.90 km) |
| Sierning to Matosinhos | 1,221.08 mi (1,965.13 km) |
| Sierning to Mealhada | 1,239.02 mi (1,994.01 km) |
| Sierning to Melgaco | 1,169.92 mi (1,882.81 km) |
| Sierning to Melres | 1,211.80 mi (1,950.20 km) |
| Sierning to Mira | 1,249.70 mi (2,011.19 km) |
| Sierning to Miranda do Corvo | 1,244.61 mi (2,003.01 km) |
| Sierning to Mirandela | 1,142.66 mi (1,838.93 km) |
| Sierning to Mogadouro | 1,127.41 mi (1,814.39 km) |
| Sierning to Moimenta da Beira | 1,179.95 mi (1,898.95 km) |
| Sierning to Moita | 1,330.75 mi (2,141.63 km) |
| Sierning to Moncao | 1,180.98 mi (1,900.60 km) |
| Sierning to Montalegre | 1,158.29 mi (1,864.08 km) |
