| Williamsport to Smolyan | 4,915.91 mi (7,911.39 km) |
| Williamsport to Sofia | 4,812.97 mi (7,745.73 km) |
| Williamsport to Sopot | 4,871.73 mi (7,840.29 km) |
| Williamsport to Sozopol | 4,997.94 mi (8,043.40 km) |
| Williamsport to Sredets | 4,981.40 mi (8,016.78 km) |
| Williamsport to Stamboliyski | 4,885.41 mi (7,862.30 km) |
| Williamsport to Stara Zagora | 4,916.78 mi (7,912.80 km) |
| Williamsport to Svilengrad | 4,967.81 mi (7,994.91 km) |
| Williamsport to Svishtov | 4,853.60 mi (7,811.11 km) |
| Williamsport to Targovishte | 4,917.61 mi (7,914.12 km) |
| Williamsport to Teteven | 4,841.08 mi (7,790.96 km) |
| Williamsport to Troyan | 4,860.35 mi (7,821.98 km) |
| Williamsport to Tryavna | 4,891.98 mi (7,872.87 km) |
| Williamsport to Tutrakan | 4,883.84 mi (7,859.79 km) |
| Williamsport to Varna | 4,970.64 mi (7,999.47 km) |
