| Opatija to Marco de Canavezes | 1,161.29 mi (1,868.91 km) |
| Opatija to Marinha Grande | 1,238.94 mi (1,993.87 km) |
| Opatija to Massama | 1,286.39 mi (2,070.25 km) |
| Opatija to Matosinhos | 1,187.85 mi (1,911.66 km) |
| Opatija to Mealhada | 1,197.31 mi (1,926.89 km) |
| Opatija to Melgaco | 1,144.51 mi (1,841.91 km) |
| Opatija to Melres | 1,176.37 mi (1,893.18 km) |
| Opatija to Mira | 1,209.52 mi (1,946.54 km) |
| Opatija to Miranda do Corvo | 1,199.85 mi (1,930.97 km) |
| Opatija to Mirandela | 1,106.90 mi (1,781.38 km) |
| Opatija to Mogadouro | 1,088.31 mi (1,751.47 km) |
| Opatija to Moimenta da Beira | 1,140.74 mi (1,835.84 km) |
| Opatija to Moita | 1,276.10 mi (2,053.68 km) |
| Opatija to Moncao | 1,155.83 mi (1,860.13 km) |
| Opatija to Montalegre | 1,128.22 mi (1,815.70 km) |
