| Harpenden to Montijo | 941.38 mi (1,515.01 km) |
| Harpenden to Montilla | 1,005.26 mi (1,617.80 km) |
| Harpenden to Montmelo | 719.61 mi (1,158.11 km) |
| Harpenden to Montornes del Valles | 720.45 mi (1,159.46 km) |
| Harpenden to Montoro | 973.33 mi (1,566.43 km) |
| Harpenden to Monzon | 685.02 mi (1,102.43 km) |
| Harpenden to Mora | 854.20 mi (1,374.70 km) |
| Harpenden to Moralzarzal | 788.77 mi (1,269.41 km) |
| Harpenden to Moron de la Frontera | 1,045.36 mi (1,682.34 km) |
| Harpenden to Mostoles | 810.91 mi (1,305.04 km) |
| Harpenden to Motril | 1,052.50 mi (1,693.84 km) |
| Harpenden to Muchamiel | 926.13 mi (1,490.46 km) |
| Harpenden to Mula | 953.40 mi (1,534.34 km) |
| Harpenden to Munguia | 596.07 mi (959.29 km) |
| Harpenden to Murcia | 956.40 mi (1,539.18 km) |
