| Castelleone to Smolyan | 790.74 mi (1,272.58 km) |
| Castelleone to Sofia | 696.92 mi (1,121.59 km) |
| Castelleone to Sopot | 766.17 mi (1,233.03 km) |
| Castelleone to Sozopol | 913.56 mi (1,470.24 km) |
| Castelleone to Sredets | 890.92 mi (1,433.79 km) |
| Castelleone to Stamboliyski | 768.14 mi (1,236.20 km) |
| Castelleone to Stara Zagora | 814.36 mi (1,310.59 km) |
| Castelleone to Svilengrad | 857.07 mi (1,379.31 km) |
| Castelleone to Svishtov | 776.26 mi (1,249.28 km) |
| Castelleone to Targovishte | 842.55 mi (1,355.96 km) |
| Castelleone to Teteven | 737.10 mi (1,186.25 km) |
| Castelleone to Troyan | 759.49 mi (1,222.28 km) |
| Castelleone to Tryavna | 797.62 mi (1,283.65 km) |
| Castelleone to Tutrakan | 831.12 mi (1,337.56 km) |
| Castelleone to Varna | 907.87 mi (1,461.08 km) |
