| Swallownest to Mangualde | 931.30 mi (1,498.79 km) |
| Swallownest to Marco de Canavezes | 899.26 mi (1,447.21 km) |
| Swallownest to Marinha Grande | 1,006.21 mi (1,619.34 km) |
| Swallownest to Massama | 1,077.11 mi (1,733.45 km) |
| Swallownest to Matosinhos | 908.57 mi (1,462.21 km) |
| Swallownest to Mealhada | 956.67 mi (1,539.61 km) |
| Swallownest to Melgaco | 840.32 mi (1,352.36 km) |
| Swallownest to Melres | 911.04 mi (1,466.17 km) |
| Swallownest to Mira | 958.09 mi (1,541.89 km) |
| Swallownest to Miranda do Corvo | 973.44 mi (1,566.60 km) |
| Swallownest to Mirandela | 864.36 mi (1,391.05 km) |
| Swallownest to Mogadouro | 867.98 mi (1,396.87 km) |
| Swallownest to Moimenta da Beira | 904.24 mi (1,455.23 km) |
| Swallownest to Moita | 1,079.42 mi (1,737.15 km) |
| Swallownest to Moncao | 846.92 mi (1,362.98 km) |
