| Letchworth to Mangualde | 863.09 mi (1,389.01 km) |
| Letchworth to Marco de Canavezes | 834.15 mi (1,342.43 km) |
| Letchworth to Marinha Grande | 941.38 mi (1,515.00 km) |
| Letchworth to Massama | 1,011.70 mi (1,628.18 km) |
| Letchworth to Matosinhos | 846.07 mi (1,361.62 km) |
| Letchworth to Mealhada | 891.09 mi (1,434.06 km) |
| Letchworth to Melgaco | 778.26 mi (1,252.49 km) |
| Letchworth to Melres | 846.82 mi (1,362.83 km) |
| Letchworth to Mira | 893.89 mi (1,438.58 km) |
| Letchworth to Miranda do Corvo | 906.73 mi (1,459.24 km) |
| Letchworth to Mirandela | 795.34 mi (1,279.98 km) |
| Letchworth to Mogadouro | 796.44 mi (1,281.75 km) |
| Letchworth to Moimenta da Beira | 836.15 mi (1,345.65 km) |
| Letchworth to Moita | 1,012.62 mi (1,629.65 km) |
| Letchworth to Moncao | 785.81 mi (1,264.64 km) |
