| Difficult Run to Castelfidardo | 4,488.58 mi (7,223.68 km) |
| Difficult Run to Castelfiorentino | 4,372.12 mi (7,036.25 km) |
| Difficult Run to Castelfranco di Sopra | 4,397.05 mi (7,076.37 km) |
| Difficult Run to Castelfranco di Sotto | 4,359.29 mi (7,015.60 km) |
| Difficult Run to Castelfranco Emilia | 4,342.21 mi (6,988.12 km) |
| Difficult Run to Castelfranco Veneto | 4,343.86 mi (6,990.76 km) |
| Difficult Run to Castellabate | 4,665.99 mi (7,509.18 km) |
| Difficult Run to Castellammare del Golfo | 4,656.36 mi (7,493.69 km) |
| Difficult Run to Castellammare di Stabia | 4,629.61 mi (7,450.64 km) |
| Difficult Run to Castellamonte | 4,172.61 mi (6,715.16 km) |
| Difficult Run to Castellana Grotte | 4,740.45 mi (7,629.01 km) |
| Difficult Run to Castellaneta | 4,739.82 mi (7,628.00 km) |
| Difficult Run to Castellanza | 4,216.39 mi (6,785.62 km) |
| Difficult Run to Castellarano | 4,331.61 mi (6,971.06 km) |
| Difficult Run to Castelleone | 4,263.64 mi (6,861.66 km) |
