| Seaford to Mangualde | 797.27 mi (1,283.08 km) |
| Seaford to Marco de Canavezes | 770.70 mi (1,240.33 km) |
| Seaford to Marinha Grande | 877.57 mi (1,412.31 km) |
| Seaford to Massama | 947.19 mi (1,524.35 km) |
| Seaford to Matosinhos | 784.44 mi (1,262.44 km) |
| Seaford to Mealhada | 826.99 mi (1,330.91 km) |
| Seaford to Melgaco | 717.42 mi (1,154.57 km) |
| Seaford to Melres | 783.95 mi (1,261.64 km) |
| Seaford to Mira | 830.77 mi (1,337.00 km) |
| Seaford to Miranda do Corvo | 841.75 mi (1,354.67 km) |
| Seaford to Mirandela | 729.32 mi (1,173.72 km) |
| Seaford to Mogadouro | 728.61 mi (1,172.59 km) |
| Seaford to Moimenta da Beira | 770.55 mi (1,240.08 km) |
| Seaford to Moita | 947.13 mi (1,524.26 km) |
| Seaford to Moncao | 725.61 mi (1,167.76 km) |
