| Merthyr Tudful to Cocentaina | 909.18 mi (1,463.18 km) |
| Merthyr Tudful to Coin | 1,043.84 mi (1,679.89 km) |
| Merthyr Tudful to Colindres | 576.68 mi (928.08 km) |
| Merthyr Tudful to Collado-Villalba | 768.19 mi (1,236.28 km) |
| Merthyr Tudful to Colmenar Viejo | 766.06 mi (1,232.85 km) |
| Merthyr Tudful to Colmenarejo | 773.21 mi (1,244.36 km) |
| Merthyr Tudful to Conil de la Frontera | 1,077.53 mi (1,734.12 km) |
| Merthyr Tudful to Consuegra | 848.61 mi (1,365.71 km) |
| Merthyr Tudful to Corbera de Llobregat | 756.20 mi (1,216.98 km) |
| Merthyr Tudful to Cordoba | 959.94 mi (1,544.88 km) |
| Merthyr Tudful to Coria del Rio | 1,007.53 mi (1,621.46 km) |
| Merthyr Tudful to Crevillente | 940.63 mi (1,513.80 km) |
| Merthyr Tudful to Cuarte de Huerva | 711.49 mi (1,145.04 km) |
| Merthyr Tudful to Cubellas | 765.95 mi (1,232.68 km) |
| Merthyr Tudful to Cuellar | 715.93 mi (1,152.18 km) |
