| Port Royal to Mangualde | 3,976.89 mi (6,400.18 km) |
| Port Royal to Marco de Canavezes | 3,945.99 mi (6,350.46 km) |
| Port Royal to Marinha Grande | 3,934.77 mi (6,332.39 km) |
| Port Royal to Massama | 3,937.41 mi (6,336.65 km) |
| Port Royal to Matosinhos | 3,918.52 mi (6,306.26 km) |
| Port Royal to Mealhada | 3,946.64 mi (6,351.50 km) |
| Port Royal to Melgaco | 3,922.42 mi (6,312.53 km) |
| Port Royal to Melres | 3,935.76 mi (6,334.00 km) |
| Port Royal to Mira | 3,931.36 mi (6,326.92 km) |
| Port Royal to Miranda do Corvo | 3,958.18 mi (6,370.07 km) |
| Port Royal to Mirandela | 3,988.24 mi (6,418.46 km) |
| Port Royal to Mogadouro | 4,014.35 mi (6,460.47 km) |
| Port Royal to Moimenta da Beira | 3,976.78 mi (6,400.00 km) |
| Port Royal to Moita | 3,954.61 mi (6,364.33 km) |
| Port Royal to Moncao | 3,912.70 mi (6,296.88 km) |
