| Siano to Marco de Canavezes | 1,188.22 mi (1,912.25 km) |
| Siano to Marinha Grande | 1,243.86 mi (2,001.79 km) |
| Siano to Massama | 1,276.54 mi (2,054.40 km) |
| Siano to Matosinhos | 1,216.64 mi (1,957.99 km) |
| Siano to Mealhada | 1,211.11 mi (1,949.09 km) |
| Siano to Melgaco | 1,188.80 mi (1,913.18 km) |
| Siano to Melres | 1,202.06 mi (1,934.53 km) |
| Siano to Mira | 1,225.30 mi (1,971.93 km) |
| Siano to Miranda do Corvo | 1,208.22 mi (1,944.45 km) |
| Siano to Mirandela | 1,136.19 mi (1,828.51 km) |
| Siano to Mogadouro | 1,113.11 mi (1,791.38 km) |
| Siano to Moimenta da Beira | 1,162.06 mi (1,870.16 km) |
| Siano to Moita | 1,263.10 mi (2,032.77 km) |
| Siano to Moncao | 1,199.89 mi (1,931.04 km) |
| Siano to Montalegre | 1,165.76 mi (1,876.11 km) |
