| South Portland to Cividale del Friuli | 3,903.17 mi (6,281.55 km) |
| South Portland to Civita Castellana | 3,995.90 mi (6,430.78 km) |
| South Portland to Civitanova Marche | 4,016.01 mi (6,463.15 km) |
| South Portland to Civitavecchia | 3,976.56 mi (6,399.65 km) |
| South Portland to Civitella in Val di Chiana | 3,925.47 mi (6,317.43 km) |
| South Portland to Clusone | 3,765.15 mi (6,059.42 km) |
| South Portland to Coccaglio | 3,777.03 mi (6,078.54 km) |
| South Portland to Codigoro | 3,892.44 mi (6,264.28 km) |
| South Portland to Codogno | 3,778.98 mi (6,081.68 km) |
| South Portland to Codroipo | 3,889.15 mi (6,258.99 km) |
| South Portland to Cogoleto | 3,759.53 mi (6,050.38 km) |
| South Portland to Colle di Val d'Elsa | 3,900.95 mi (6,277.97 km) |
| South Portland to Colle Salvetti | 3,865.88 mi (6,221.53 km) |
| South Portland to Collecchio | 3,814.68 mi (6,139.13 km) |
| South Portland to Colleferro | 4,042.99 mi (6,506.57 km) |
