| Cuellar to Smolyan | 1,494.49 mi (2,405.15 km) |
| Cuellar to Sofia | 1,414.77 mi (2,276.86 km) |
| Cuellar to Sopot | 1,486.86 mi (2,392.87 km) |
| Cuellar to Sozopol | 1,637.86 mi (2,635.88 km) |
| Cuellar to Sredets | 1,613.30 mi (2,596.35 km) |
| Cuellar to Stamboliyski | 1,480.37 mi (2,382.42 km) |
| Cuellar to Stara Zagora | 1,534.17 mi (2,469.01 km) |
| Cuellar to Svilengrad | 1,568.83 mi (2,524.79 km) |
| Cuellar to Svishtov | 1,510.52 mi (2,430.94 km) |
| Cuellar to Targovishte | 1,574.46 mi (2,533.85 km) |
| Cuellar to Teteven | 1,460.52 mi (2,350.47 km) |
| Cuellar to Troyan | 1,483.41 mi (2,387.32 km) |
| Cuellar to Tryavna | 1,522.96 mi (2,450.97 km) |
| Cuellar to Tutrakan | 1,571.22 mi (2,528.64 km) |
| Cuellar to Varna | 1,641.42 mi (2,641.61 km) |
