| Potters Bar to Montalegre | 770.52 mi (1,240.03 km) |
| Potters Bar to Montemor-o-Novo | 981.36 mi (1,579.35 km) |
| Potters Bar to Montemor-o-Velho | 893.93 mi (1,438.64 km) |
| Potters Bar to Montijo | 992.71 mi (1,597.61 km) |
| Potters Bar to Mortagua | 867.50 mi (1,396.10 km) |
| Potters Bar to Moura | 1,001.19 mi (1,611.26 km) |
| Potters Bar to Murtosa | 857.25 mi (1,379.60 km) |
| Potters Bar to Nazare | 937.97 mi (1,509.52 km) |
| Potters Bar to Nelas | 854.28 mi (1,374.84 km) |
| Potters Bar to Obidos | 955.22 mi (1,537.28 km) |
| Potters Bar to Odemira | 1,058.33 mi (1,703.22 km) |
| Potters Bar to Odivelas | 991.68 mi (1,595.96 km) |
| Potters Bar to Oeiras | 1,001.38 mi (1,611.56 km) |
| Potters Bar to Olhao | 1,080.56 mi (1,739.00 km) |
| Potters Bar to Oliveira de Azemeis | 847.06 mi (1,363.22 km) |
