| Duncan to Cocentaina | 5,131.12 mi (8,257.74 km) |
| Duncan to Coin | 5,003.77 mi (8,052.78 km) |
| Duncan to Colindres | 4,832.95 mi (7,777.89 km) |
| Duncan to Collado-Villalba | 4,901.42 mi (7,888.07 km) |
| Duncan to Colmenar Viejo | 4,911.59 mi (7,904.44 km) |
| Duncan to Colmenarejo | 4,903.50 mi (7,891.42 km) |
| Duncan to Conil de la Frontera | 4,953.55 mi (7,971.97 km) |
| Duncan to Consuegra | 4,960.17 mi (7,982.62 km) |
| Duncan to Corbera de Llobregat | 5,138.65 mi (8,269.86 km) |
| Duncan to Cordoba | 4,960.04 mi (7,982.41 km) |
| Duncan to Coria del Rio | 4,920.32 mi (7,918.49 km) |
| Duncan to Crevillente | 5,132.35 mi (8,259.72 km) |
| Duncan to Cuarte de Huerva | 5,007.30 mi (8,058.48 km) |
| Duncan to Cubellas | 5,135.05 mi (8,264.07 km) |
| Duncan to Cuellar | 4,861.51 mi (7,823.84 km) |
