| Diamond Bar to Cortona | 6,230.59 mi (10,027.17 km) |
| Diamond Bar to Cosenza | 6,583.18 mi (10,594.60 km) |
| Diamond Bar to Cossato | 5,987.53 mi (9,636.00 km) |
| Diamond Bar to Costa Volpino | 6,035.76 mi (9,713.61 km) |
| Diamond Bar to Creazzo | 6,094.71 mi (9,808.49 km) |
| Diamond Bar to Crema | 6,046.73 mi (9,731.28 km) |
| Diamond Bar to Cremona | 6,070.08 mi (9,768.84 km) |
| Diamond Bar to Crevalcore | 6,127.46 mi (9,861.19 km) |
| Diamond Bar to Crispiano | 6,541.73 mi (10,527.90 km) |
| Diamond Bar to Crosia | 6,584.80 mi (10,597.21 km) |
| Diamond Bar to Crotone | 6,622.79 mi (10,658.36 km) |
| Diamond Bar to Cuneo | 6,027.57 mi (9,700.44 km) |
| Diamond Bar to Cuorgne | 5,979.68 mi (9,623.36 km) |
| Diamond Bar to Cusano Milanino | 6,021.22 mi (9,690.21 km) |
| Diamond Bar to Cutro | 6,621.36 mi (10,656.04 km) |
