| South Portland to Collegno | 3,690.49 mi (5,939.26 km) |
| South Portland to Cologno al Serio | 3,764.58 mi (6,058.51 km) |
| South Portland to Cologno Monzese | 3,748.52 mi (6,032.66 km) |
| South Portland to Colorno | 3,815.52 mi (6,140.48 km) |
| South Portland to Comacchio | 3,899.93 mi (6,276.34 km) |
| South Portland to Comiso | 4,297.98 mi (6,916.93 km) |
| South Portland to Como | 3,731.06 mi (6,004.57 km) |
| South Portland to Concordia Sagittaria | 3,890.60 mi (6,261.31 km) |
| South Portland to Concorezzo | 3,748.94 mi (6,033.33 km) |
| South Portland to Conegliano | 3,863.42 mi (6,217.57 km) |
| South Portland to Conselice | 3,891.54 mi (6,262.83 km) |
| South Portland to Conselve | 3,867.97 mi (6,224.89 km) |
| South Portland to Conversano | 4,249.42 mi (6,838.78 km) |
| South Portland to Copertino | 4,317.25 mi (6,947.95 km) |
| South Portland to Copparo | 3,878.14 mi (6,241.26 km) |
