| Boston to Cocentaina | 983.33 mi (1,582.52 km) |
| Boston to Coin | 1,149.68 mi (1,850.23 km) |
| Boston to Colindres | 680.09 mi (1,094.50 km) |
| Boston to Collado-Villalba | 872.91 mi (1,404.81 km) |
| Boston to Colmenar Viejo | 868.80 mi (1,398.21 km) |
| Boston to Colmenarejo | 877.91 mi (1,412.86 km) |
| Boston to Conil de la Frontera | 1,191.18 mi (1,917.01 km) |
| Boston to Consuegra | 948.89 mi (1,527.09 km) |
| Boston to Corbera de Llobregat | 803.68 mi (1,293.40 km) |
| Boston to Cordoba | 1,067.21 mi (1,717.50 km) |
| Boston to Coria del Rio | 1,122.26 mi (1,806.10 km) |
| Boston to Crevillente | 1,018.12 mi (1,638.51 km) |
| Boston to Cuarte de Huerva | 788.12 mi (1,268.36 km) |
| Boston to Cubellas | 816.65 mi (1,314.28 km) |
| Boston to Cuellar | 824.25 mi (1,326.50 km) |
