| Castel Bolognese to Smolyan | 678.34 mi (1,091.69 km) |
| Castel Bolognese to Sofia | 587.96 mi (946.23 km) |
| Castel Bolognese to Sopot | 658.62 mi (1,059.94 km) |
| Castel Bolognese to Sozopol | 808.03 mi (1,300.40 km) |
| Castel Bolognese to Sredets | 784.57 mi (1,262.64 km) |
| Castel Bolognese to Stamboliyski | 657.84 mi (1,058.70 km) |
| Castel Bolognese to Stara Zagora | 706.74 mi (1,137.39 km) |
| Castel Bolognese to Svilengrad | 747.12 mi (1,202.38 km) |
| Castel Bolognese to Svishtov | 674.79 mi (1,085.98 km) |
| Castel Bolognese to Targovishte | 740.09 mi (1,191.06 km) |
| Castel Bolognese to Teteven | 630.42 mi (1,014.57 km) |
| Castel Bolognese to Troyan | 653.13 mi (1,051.11 km) |
| Castel Bolognese to Tryavna | 692.02 mi (1,113.70 km) |
| Castel Bolognese to Tutrakan | 733.37 mi (1,180.24 km) |
| Castel Bolognese to Varna | 806.44 mi (1,297.84 km) |
