| Opera to Marco de Canavezes | 918.27 mi (1,477.82 km) |
| Opera to Marinha Grande | 999.41 mi (1,608.39 km) |
| Opera to Massama | 1,049.84 mi (1,689.55 km) |
| Opera to Matosinhos | 944.39 mi (1,519.85 km) |
| Opera to Mealhada | 956.33 mi (1,539.07 km) |
| Opera to Melgaco | 899.32 mi (1,447.31 km) |
| Opera to Melres | 933.45 mi (1,502.24 km) |
| Opera to Mira | 968.08 mi (1,557.97 km) |
| Opera to Miranda do Corvo | 959.93 mi (1,544.86 km) |
| Opera to Mirandela | 863.89 mi (1,390.30 km) |
| Opera to Mogadouro | 846.20 mi (1,361.83 km) |
| Opera to Moimenta da Beira | 898.82 mi (1,446.50 km) |
| Opera to Moita | 1,040.44 mi (1,674.43 km) |
| Opera to Moncao | 910.61 mi (1,465.49 km) |
| Opera to Montalegre | 883.89 mi (1,422.49 km) |
