| Prestonpans to Mangualde | 1,083.02 mi (1,742.96 km) |
| Prestonpans to Marco de Canavezes | 1,047.41 mi (1,685.65 km) |
| Prestonpans to Marinha Grande | 1,152.65 mi (1,855.00 km) |
| Prestonpans to Massama | 1,223.55 mi (1,969.11 km) |
| Prestonpans to Matosinhos | 1,053.23 mi (1,695.01 km) |
| Prestonpans to Mealhada | 1,104.68 mi (1,777.82 km) |
| Prestonpans to Melgaco | 985.46 mi (1,585.95 km) |
| Prestonpans to Melres | 1,057.88 mi (1,702.49 km) |
| Prestonpans to Mira | 1,104.27 mi (1,777.15 km) |
| Prestonpans to Miranda do Corvo | 1,122.72 mi (1,806.85 km) |
| Prestonpans to Mirandela | 1,017.94 mi (1,638.22 km) |
| Prestonpans to Mogadouro | 1,024.64 mi (1,649.00 km) |
| Prestonpans to Moimenta da Beira | 1,056.13 mi (1,699.68 km) |
| Prestonpans to Moita | 1,227.68 mi (1,975.76 km) |
| Prestonpans to Moncao | 990.73 mi (1,594.43 km) |
