| Castelo Branco to Smolyan | 1,681.32 mi (2,705.83 km) |
| Castelo Branco to Sofia | 1,604.65 mi (2,582.43 km) |
| Castelo Branco to Sopot | 1,676.85 mi (2,698.63 km) |
| Castelo Branco to Sozopol | 1,827.89 mi (2,941.70 km) |
| Castelo Branco to Sredets | 1,803.03 mi (2,901.70 km) |
| Castelo Branco to Stamboliyski | 1,668.83 mi (2,685.72 km) |
| Castelo Branco to Stara Zagora | 1,723.76 mi (2,774.12 km) |
| Castelo Branco to Svilengrad | 1,756.70 mi (2,827.13 km) |
| Castelo Branco to Svishtov | 1,703.07 mi (2,740.83 km) |
| Castelo Branco to Targovishte | 1,766.31 mi (2,842.59 km) |
| Castelo Branco to Teteven | 1,651.16 mi (2,657.28 km) |
| Castelo Branco to Troyan | 1,674.03 mi (2,694.09 km) |
| Castelo Branco to Tryavna | 1,713.68 mi (2,757.89 km) |
| Castelo Branco to Tutrakan | 1,764.86 mi (2,840.27 km) |
| Castelo Branco to Varna | 1,833.40 mi (2,950.58 km) |
