| Potomac to Clacton-on-Sea | 3,711.46 mi (5,973.02 km) |
| Potomac to Clay Cross | 3,579.84 mi (5,761.20 km) |
| Potomac to Clayton | 3,552.07 mi (5,716.51 km) |
| Potomac to Clayton le Moors | 3,529.78 mi (5,680.63 km) |
| Potomac to Cleckheaton | 3,556.87 mi (5,724.22 km) |
| Potomac to Cleethorpes | 3,626.89 mi (5,836.91 km) |
| Potomac to Clevedon | 3,555.99 mi (5,722.81 km) |
| Potomac to Clifton | 3,594.40 mi (5,784.63 km) |
| Potomac to Clifton | 3,576.46 mi (5,755.75 km) |
| Potomac to Cliftonville | 3,731.25 mi (6,004.86 km) |
| Potomac to Clitheroe | 3,527.71 mi (5,677.30 km) |
| Potomac to Clydebank | 3,416.55 mi (5,498.41 km) |
| Potomac to Coalville | 3,590.36 mi (5,778.13 km) |
| Potomac to Coatbridge | 3,431.26 mi (5,522.08 km) |
| Potomac to Cobham | 3,658.67 mi (5,888.06 km) |
