| Potomac to Cadiz | 3,773.50 mi (6,072.86 km) |
| Potomac to Calafell | 4,013.69 mi (6,459.42 km) |
| Potomac to Calahorra | 3,816.41 mi (6,141.92 km) |
| Potomac to Calasparra | 3,948.70 mi (6,354.83 km) |
| Potomac to Calatayud | 3,859.01 mi (6,210.47 km) |
| Potomac to Caldas de Montbuy | 4,028.35 mi (6,483.00 km) |
| Potomac to Caldas de Reyes | 3,493.66 mi (5,622.50 km) |
| Potomac to Calella | 4,051.84 mi (6,520.80 km) |
| Potomac to Callosa de Segura | 3,991.88 mi (6,424.31 km) |
| Potomac to Calpe | 4,020.21 mi (6,469.90 km) |
| Potomac to Calvia | 4,108.59 mi (6,612.13 km) |
| Potomac to Camas | 3,760.84 mi (6,052.49 km) |
| Potomac to Cambados | 3,488.44 mi (5,614.11 km) |
| Potomac to Cambre | 3,491.79 mi (5,619.49 km) |
| Potomac to Cambrils | 3,993.76 mi (6,427.34 km) |
