| Hillsborough to Smolyan | 4,850.57 mi (7,806.24 km) |
| Hillsborough to Sofia | 4,748.22 mi (7,641.52 km) |
| Hillsborough to Sopot | 4,808.28 mi (7,738.18 km) |
| Hillsborough to Sozopol | 4,937.07 mi (7,945.45 km) |
| Hillsborough to Sredets | 4,919.90 mi (7,917.82 km) |
| Hillsborough to Stamboliyski | 4,820.85 mi (7,758.41 km) |
| Hillsborough to Stara Zagora | 4,853.86 mi (7,811.53 km) |
| Hillsborough to Svilengrad | 4,904.30 mi (7,892.70 km) |
| Hillsborough to Svishtov | 4,792.44 mi (7,712.68 km) |
| Hillsborough to Targovishte | 4,857.03 mi (7,816.64 km) |
| Hillsborough to Teteven | 4,777.62 mi (7,688.84 km) |
| Hillsborough to Troyan | 4,797.28 mi (7,720.47 km) |
| Hillsborough to Tryavna | 4,829.65 mi (7,772.57 km) |
| Hillsborough to Tutrakan | 4,824.70 mi (7,764.61 km) |
| Hillsborough to Varna | 4,911.36 mi (7,904.08 km) |
