| Thornton Heath to Mangualde | 830.37 mi (1,336.35 km) |
| Thornton Heath to Marco de Canavezes | 802.44 mi (1,291.40 km) |
| Thornton Heath to Marinha Grande | 909.57 mi (1,463.81 km) |
| Thornton Heath to Massama | 979.62 mi (1,576.54 km) |
| Thornton Heath to Matosinhos | 815.16 mi (1,311.88 km) |
| Thornton Heath to Mealhada | 859.13 mi (1,382.63 km) |
| Thornton Heath to Melgaco | 747.65 mi (1,203.22 km) |
| Thornton Heath to Melres | 815.37 mi (1,312.21 km) |
| Thornton Heath to Mira | 862.36 mi (1,387.84 km) |
| Thornton Heath to Miranda do Corvo | 874.40 mi (1,407.21 km) |
| Thornton Heath to Mirandela | 762.50 mi (1,227.12 km) |
| Thornton Heath to Mogadouro | 762.82 mi (1,227.65 km) |
| Thornton Heath to Moimenta da Beira | 803.51 mi (1,293.13 km) |
| Thornton Heath to Moita | 980.11 mi (1,577.33 km) |
| Thornton Heath to Moncao | 755.48 mi (1,215.83 km) |
