| Allentown to Smolyan | 4,880.55 mi (7,854.49 km) |
| Allentown to Sofia | 4,778.03 mi (7,689.50 km) |
| Allentown to Sopot | 4,837.74 mi (7,785.60 km) |
| Allentown to Sozopol | 4,965.84 mi (7,991.75 km) |
| Allentown to Sredets | 4,948.84 mi (7,964.39 km) |
| Allentown to Stamboliyski | 4,850.61 mi (7,806.31 km) |
| Allentown to Stara Zagora | 4,883.18 mi (7,858.72 km) |
| Allentown to Svilengrad | 4,933.78 mi (7,940.16 km) |
| Allentown to Svishtov | 4,821.27 mi (7,759.09 km) |
| Allentown to Targovishte | 4,885.71 mi (7,862.80 km) |
| Allentown to Teteven | 4,807.08 mi (7,736.25 km) |
| Allentown to Troyan | 4,826.63 mi (7,767.72 km) |
| Allentown to Tryavna | 4,858.81 mi (7,819.50 km) |
| Allentown to Tutrakan | 4,852.99 mi (7,810.12 km) |
| Allentown to Varna | 4,939.69 mi (7,949.67 km) |
