| Merthyr Tudful to Montalegre | 716.16 mi (1,152.55 km) |
| Merthyr Tudful to Montemor-o-Novo | 934.28 mi (1,503.58 km) |
| Merthyr Tudful to Montemor-o-Velho | 838.89 mi (1,350.07 km) |
| Merthyr Tudful to Montijo | 940.83 mi (1,514.12 km) |
| Merthyr Tudful to Mortagua | 814.86 mi (1,311.39 km) |
| Merthyr Tudful to Moura | 960.81 mi (1,546.27 km) |
| Merthyr Tudful to Murtosa | 800.55 mi (1,288.36 km) |
| Merthyr Tudful to Nazare | 882.13 mi (1,419.65 km) |
| Merthyr Tudful to Nelas | 804.28 mi (1,294.37 km) |
| Merthyr Tudful to Obidos | 899.53 mi (1,447.66 km) |
| Merthyr Tudful to Odemira | 1,011.18 mi (1,627.34 km) |
| Merthyr Tudful to Odivelas | 937.61 mi (1,508.93 km) |
| Merthyr Tudful to Oeiras | 946.71 mi (1,523.59 km) |
| Merthyr Tudful to Olhao | 1,039.95 mi (1,673.63 km) |
| Merthyr Tudful to Oliveira de Azemeis | 791.16 mi (1,273.24 km) |
