| Upminster to Cocentaina | 885.76 mi (1,425.50 km) |
| Upminster to Coin | 1,057.59 mi (1,702.02 km) |
| Upminster to Colindres | 589.41 mi (948.57 km) |
| Upminster to Collado-Villalba | 781.43 mi (1,257.58 km) |
| Upminster to Colmenar Viejo | 776.79 mi (1,250.12 km) |
| Upminster to Colmenarejo | 786.40 mi (1,265.59 km) |
| Upminster to Conil de la Frontera | 1,101.38 mi (1,772.50 km) |
| Upminster to Consuegra | 855.91 mi (1,377.45 km) |
| Upminster to Corbera de Llobregat | 705.02 mi (1,134.62 km) |
| Upminster to Cordoba | 975.75 mi (1,570.31 km) |
| Upminster to Coria del Rio | 1,033.03 mi (1,662.50 km) |
| Upminster to Crevillente | 920.87 mi (1,481.99 km) |
| Upminster to Cuarte de Huerva | 691.23 mi (1,112.43 km) |
| Upminster to Cubellas | 717.99 mi (1,155.49 km) |
| Upminster to Cuellar | 734.10 mi (1,181.42 km) |
