| Duncanville to Smolyan | 6,107.94 mi (9,829.78 km) |
| Duncanville to Sofia | 6,003.90 mi (9,662.34 km) |
| Duncanville to Sopot | 6,058.43 mi (9,750.10 km) |
| Duncanville to Sozopol | 6,175.78 mi (9,938.96 km) |
| Duncanville to Sredets | 6,161.35 mi (9,915.74 km) |
| Duncanville to Stamboliyski | 6,075.33 mi (9,777.31 km) |
| Duncanville to Stara Zagora | 6,101.61 mi (9,819.60 km) |
| Duncanville to Svilengrad | 6,154.11 mi (9,904.08 km) |
| Duncanville to Svishtov | 6,033.37 mi (9,709.77 km) |
| Duncanville to Targovishte | 6,095.06 mi (9,809.05 km) |
| Duncanville to Teteven | 6,028.00 mi (9,701.13 km) |
| Duncanville to Troyan | 6,045.99 mi (9,730.08 km) |
| Duncanville to Tryavna | 6,075.12 mi (9,776.96 km) |
| Duncanville to Tutrakan | 6,056.89 mi (9,747.63 km) |
| Duncanville to Varna | 6,143.49 mi (9,886.99 km) |
