| Harrow to Mangualde | 836.64 mi (1,346.44 km) |
| Harrow to Marco de Canavezes | 808.06 mi (1,300.45 km) |
| Harrow to Marinha Grande | 915.26 mi (1,472.98 km) |
| Harrow to Massama | 985.49 mi (1,585.99 km) |
| Harrow to Matosinhos | 820.29 mi (1,320.13 km) |
| Harrow to Mealhada | 864.91 mi (1,391.94 km) |
| Harrow to Melgaco | 752.59 mi (1,211.18 km) |
| Harrow to Melres | 820.83 mi (1,321.00 km) |
| Harrow to Mira | 867.88 mi (1,396.71 km) |
| Harrow to Miranda do Corvo | 880.42 mi (1,416.90 km) |
| Harrow to Mirandela | 768.84 mi (1,237.33 km) |
| Harrow to Mogadouro | 769.68 mi (1,238.68 km) |
| Harrow to Moimenta da Beira | 809.72 mi (1,303.12 km) |
| Harrow to Moita | 986.25 mi (1,587.21 km) |
| Harrow to Moncao | 760.25 mi (1,223.51 km) |
