| Watford to Irun | 578.30 mi (930.69 km) |
| Watford to Isla-Cristina | 1,054.46 mi (1,697.00 km) |
| Watford to Jaca | 629.14 mi (1,012.50 km) |
| Watford to Jaen | 973.52 mi (1,566.73 km) |
| Watford to Jerez de la Frontera | 1,072.14 mi (1,725.44 km) |
| Watford to Jerez de los Caballeros | 971.66 mi (1,563.74 km) |
| Watford to Jodar | 965.72 mi (1,554.17 km) |
| Watford to Jumilla | 911.47 mi (1,466.87 km) |
| Watford to La Algaba | 1,018.76 mi (1,639.53 km) |
| Watford to La Baneza | 696.20 mi (1,120.43 km) |
| Watford to La Carlota | 991.39 mi (1,595.49 km) |
| Watford to La Carolina | 938.11 mi (1,509.74 km) |
| Watford to La Corredoria | 624.52 mi (1,005.06 km) |
| Watford to La Eliana | 835.29 mi (1,344.26 km) |
| Watford to La Escala | 679.79 mi (1,094.02 km) |
