| Watford to Argentona | 710.17 mi (1,142.92 km) |
| Watford to Arico el Nuevo | 1,822.79 mi (2,933.50 km) |
| Watford to Armilla | 1,014.47 mi (1,632.63 km) |
| Watford to Arnedo | 657.01 mi (1,057.36 km) |
| Watford to Arona | 1,832.91 mi (2,949.78 km) |
| Watford to Arrecife | 1,708.15 mi (2,749.01 km) |
| Watford to Arrigorriaga | 595.04 mi (957.63 km) |
| Watford to Arroyomolinos | 804.41 mi (1,294.57 km) |
| Watford to Arteijo | 689.37 mi (1,109.43 km) |
| Watford to Arucas | 1,804.98 mi (2,904.84 km) |
| Watford to Aspe | 919.77 mi (1,480.22 km) |
| Watford to Astorga | 688.61 mi (1,108.20 km) |
| Watford to Atarfe | 1,010.05 mi (1,625.51 km) |
| Watford to Avila | 787.22 mi (1,266.91 km) |
| Watford to Aviles | 615.26 mi (990.16 km) |
