| Watford to Masanasa | 846.16 mi (1,361.77 km) |
| Watford to Masquefa | 709.11 mi (1,141.20 km) |
| Watford to Matadepera | 703.81 mi (1,132.67 km) |
| Watford to Mazarron | 972.25 mi (1,564.69 km) |
| Watford to Meco | 779.58 mi (1,254.62 km) |
| Watford to Medina del Campo | 746.73 mi (1,201.74 km) |
| Watford to Medina Sidonia | 1,083.83 mi (1,744.26 km) |
| Watford to Mejorada del Campo | 790.81 mi (1,272.69 km) |
| Watford to Meliana | 837.95 mi (1,348.55 km) |
| Watford to Mengibar | 960.07 mi (1,545.08 km) |
| Watford to Merida | 926.59 mi (1,491.20 km) |
| Watford to Miajadas | 906.06 mi (1,458.16 km) |
| Watford to Mieres | 632.33 mi (1,017.64 km) |
| Watford to Miguelturra | 893.25 mi (1,437.54 km) |
| Watford to Mijas | 1,060.75 mi (1,707.12 km) |
