| Boulder to Cividale del Friuli | 5,386.79 mi (8,669.21 km) |
| Boulder to Civita Castellana | 5,542.81 mi (8,920.30 km) |
| Boulder to Civitanova Marche | 5,538.11 mi (8,912.73 km) |
| Boulder to Civitavecchia | 5,531.06 mi (8,901.38 km) |
| Boulder to Civitella in Val di Chiana | 5,462.61 mi (8,791.22 km) |
| Boulder to Clusone | 5,280.44 mi (8,498.05 km) |
| Boulder to Coccaglio | 5,296.93 mi (8,524.59 km) |
| Boulder to Codigoro | 5,406.01 mi (8,700.12 km) |
| Boulder to Codogno | 5,307.03 mi (8,540.84 km) |
| Boulder to Codroipo | 5,378.68 mi (8,656.16 km) |
| Boulder to Cogoleto | 5,307.00 mi (8,540.80 km) |
| Boulder to Colle di Val d'Elsa | 5,443.02 mi (8,759.69 km) |
| Boulder to Colle Salvetti | 5,410.31 mi (8,707.05 km) |
| Boulder to Collecchio | 5,344.74 mi (8,601.53 km) |
| Boulder to Colleferro | 5,592.47 mi (9,000.22 km) |
