| Guadarrama to Ifield | 745.52 mi (1,199.80 km) |
| Guadarrama to Ilford | 777.85 mi (1,251.83 km) |
| Guadarrama to Ilfracombe | 727.91 mi (1,171.46 km) |
| Guadarrama to Ilkeston | 859.66 mi (1,383.48 km) |
| Guadarrama to Ilkley | 921.65 mi (1,483.26 km) |
| Guadarrama to Immingham | 912.11 mi (1,467.89 km) |
| Guadarrama to Ince-in-Makerfield | 891.76 mi (1,435.14 km) |
| Guadarrama to Inverness | 1,161.13 mi (1,868.66 km) |
| Guadarrama to Inverurie | 1,149.97 mi (1,850.70 km) |
| Guadarrama to Ipswich | 824.97 mi (1,327.65 km) |
| Guadarrama to Irlam | 885.89 mi (1,425.70 km) |
| Guadarrama to Irthlingborough | 821.56 mi (1,322.17 km) |
| Guadarrama to Irvine | 1,033.09 mi (1,662.59 km) |
| Guadarrama to Islington | 774.71 mi (1,246.78 km) |
| Guadarrama to Iver | 768.69 mi (1,237.08 km) |
