| Castalla to Smolyan | 1,351.84 mi (2,175.58 km) |
| Castalla to Sofia | 1,285.04 mi (2,068.08 km) |
| Castalla to Sopot | 1,356.76 mi (2,183.50 km) |
| Castalla to Sozopol | 1,506.33 mi (2,424.21 km) |
| Castalla to Sredets | 1,480.77 mi (2,383.07 km) |
| Castalla to Stamboliyski | 1,344.05 mi (2,163.05 km) |
| Castalla to Stara Zagora | 1,401.83 mi (2,256.03 km) |
| Castalla to Svilengrad | 1,429.28 mi (2,300.20 km) |
| Castalla to Svishtov | 1,392.05 mi (2,240.29 km) |
| Castalla to Targovishte | 1,451.77 mi (2,336.40 km) |
| Castalla to Teteven | 1,333.56 mi (2,146.16 km) |
| Castalla to Troyan | 1,356.10 mi (2,182.44 km) |
| Castalla to Tryavna | 1,395.61 mi (2,246.02 km) |
| Castalla to Tutrakan | 1,457.76 mi (2,346.04 km) |
| Castalla to Varna | 1,518.69 mi (2,444.10 km) |
