| Castellanza to Smolyan | 836.54 mi (1,346.28 km) |
| Castellanza to Sofia | 741.95 mi (1,194.06 km) |
| Castellanza to Sopot | 810.78 mi (1,304.82 km) |
| Castellanza to Sozopol | 957.51 mi (1,540.96 km) |
| Castellanza to Sredets | 935.10 mi (1,504.90 km) |
| Castellanza to Stamboliyski | 813.44 mi (1,309.10 km) |
| Castellanza to Stara Zagora | 858.94 mi (1,382.34 km) |
| Castellanza to Svilengrad | 902.22 mi (1,451.98 km) |
| Castellanza to Svishtov | 819.25 mi (1,318.45 km) |
| Castellanza to Targovishte | 885.72 mi (1,425.43 km) |
| Castellanza to Teteven | 781.51 mi (1,257.73 km) |
| Castellanza to Troyan | 803.80 mi (1,293.59 km) |
| Castellanza to Tryavna | 841.69 mi (1,354.57 km) |
| Castellanza to Tutrakan | 872.99 mi (1,404.94 km) |
| Castellanza to Varna | 950.68 mi (1,529.98 km) |
