| Castleford to Mangualde | 953.65 mi (1,534.74 km) |
| Castleford to Marco de Canavezes | 921.25 mi (1,482.60 km) |
| Castleford to Marinha Grande | 1,028.10 mi (1,654.57 km) |
| Castleford to Massama | 1,099.05 mi (1,768.74 km) |
| Castleford to Matosinhos | 930.23 mi (1,497.07 km) |
| Castleford to Mealhada | 978.68 mi (1,575.03 km) |
| Castleford to Melgaco | 861.97 mi (1,387.21 km) |
| Castleford to Melres | 932.91 mi (1,501.37 km) |
| Castleford to Mira | 979.93 mi (1,577.04 km) |
| Castleford to Miranda do Corvo | 995.58 mi (1,602.24 km) |
| Castleford to Mirandela | 886.83 mi (1,427.21 km) |
| Castleford to Mogadouro | 890.73 mi (1,433.49 km) |
| Castleford to Moimenta da Beira | 926.58 mi (1,491.19 km) |
| Castleford to Moita | 1,101.52 mi (1,772.72 km) |
| Castleford to Moncao | 868.45 mi (1,397.63 km) |
