| Merthyr Tudful to Cicero (Illinois) | 3,822.18 mi (6,151.20 km) |
| Merthyr Tudful to Cimarron Hills (Colorado) | 4,597.86 mi (7,399.53 km) |
| Merthyr Tudful to Cincinnati (Ohio) | 3,818.65 mi (6,145.53 km) |
| Merthyr Tudful to Cinco Ranch (Texas) | 4,730.03 mi (7,612.25 km) |
| Merthyr Tudful to Circleville (Ohio) | 3,734.49 mi (6,010.08 km) |
| Merthyr Tudful to Citrus (California) | 5,308.83 mi (8,543.74 km) |
| Merthyr Tudful to Citrus Heights (California) | 5,157.88 mi (8,300.80 km) |
| Merthyr Tudful to Citrus Park (Florida) | 4,272.22 mi (6,875.48 km) |
| Merthyr Tudful to Claiborne (Louisiana) | 4,445.17 mi (7,153.81 km) |
| Merthyr Tudful to Claremont (California) | 5,302.52 mi (8,533.58 km) |
| Merthyr Tudful to Claremont (New Hampshire) | 3,143.78 mi (5,059.42 km) |
| Merthyr Tudful to Claremore (Oklahoma) | 4,390.04 mi (7,065.08 km) |
| Merthyr Tudful to Clarksburg (Maryland) | 3,521.96 mi (5,668.05 km) |
| Merthyr Tudful to Clarksburg (West Virginia) | 3,643.82 mi (5,864.17 km) |
| Merthyr Tudful to Clarksdale (Mississippi) | 4,297.58 mi (6,916.29 km) |
