| Thorne to Smolyan | 1,443.03 mi (2,322.34 km) |
| Thorne to Sofia | 1,339.04 mi (2,154.98 km) |
| Thorne to Sopot | 1,394.79 mi (2,244.71 km) |
| Thorne to Sozopol | 1,518.56 mi (2,443.88 km) |
| Thorne to Sredets | 1,502.22 mi (2,417.59 km) |
| Thorne to Stamboliyski | 1,410.68 mi (2,270.27 km) |
| Thorne to Stara Zagora | 1,438.96 mi (2,315.79 km) |
| Thorne to Svilengrad | 1,490.76 mi (2,399.15 km) |
| Thorne to Svishtov | 1,374.32 mi (2,211.75 km) |
| Thorne to Targovishte | 1,438.21 mi (2,314.57 km) |
| Thorne to Teteven | 1,364.24 mi (2,195.53 km) |
| Thorne to Troyan | 1,382.84 mi (2,225.47 km) |
| Thorne to Tryavna | 1,413.48 mi (2,274.78 km) |
| Thorne to Tutrakan | 1,405.00 mi (2,261.14 km) |
| Thorne to Varna | 1,491.71 mi (2,400.67 km) |
