| Portsmouth to Castelfidardo | 852.11 mi (1,371.34 km) |
| Portsmouth to Castelfiorentino | 752.01 mi (1,210.24 km) |
| Portsmouth to Castelfranco di Sopra | 771.77 mi (1,242.04 km) |
| Portsmouth to Castelfranco di Sotto | 739.49 mi (1,190.10 km) |
| Portsmouth to Castelfranco Emilia | 707.54 mi (1,138.68 km) |
| Portsmouth to Castelfranco Veneto | 695.07 mi (1,118.61 km) |
| Portsmouth to Castellabate | 1,059.49 mi (1,705.08 km) |
| Portsmouth to Castellammare del Golfo | 1,116.24 mi (1,796.42 km) |
| Portsmouth to Castellammare di Stabia | 1,021.52 mi (1,643.98 km) |
| Portsmouth to Castellamonte | 551.88 mi (888.16 km) |
| Portsmouth to Castellana Grotte | 1,109.26 mi (1,785.19 km) |
| Portsmouth to Castellaneta | 1,112.75 mi (1,790.79 km) |
| Portsmouth to Castellanza | 582.25 mi (937.04 km) |
| Portsmouth to Castellarano | 699.06 mi (1,125.03 km) |
| Portsmouth to Castelleone | 628.21 mi (1,011.01 km) |
