| Diamond Bar to Collegno | 5,993.01 mi (9,644.82 km) |
| Diamond Bar to Cologno al Serio | 6,036.00 mi (9,714.01 km) |
| Diamond Bar to Cologno Monzese | 6,025.37 mi (9,696.90 km) |
| Diamond Bar to Colorno | 6,091.70 mi (9,803.65 km) |
| Diamond Bar to Comacchio | 6,160.82 mi (9,914.88 km) |
| Diamond Bar to Comiso | 6,657.75 mi (10,714.62 km) |
| Diamond Bar to Como | 6,004.65 mi (9,663.55 km) |
| Diamond Bar to Concordia Sagittaria | 6,124.21 mi (9,855.96 km) |
| Diamond Bar to Concorezzo | 6,024.05 mi (9,694.77 km) |
| Diamond Bar to Conegliano | 6,100.97 mi (9,818.56 km) |
| Diamond Bar to Conselice | 6,159.62 mi (9,912.95 km) |
| Diamond Bar to Conselve | 6,122.55 mi (9,853.29 km) |
| Diamond Bar to Conversano | 6,517.65 mi (10,489.15 km) |
| Diamond Bar to Copertino | 6,585.50 mi (10,598.34 km) |
| Diamond Bar to Copparo | 6,139.23 mi (9,880.14 km) |
