| Herndon to Smolyan | 5,030.26 mi (8,095.42 km) |
| Herndon to Sofia | 4,927.86 mi (7,930.62 km) |
| Herndon to Sopot | 4,987.80 mi (8,027.08 km) |
| Herndon to Sozopol | 5,116.28 mi (8,233.86 km) |
| Herndon to Sredets | 5,099.20 mi (8,206.36 km) |
| Herndon to Stamboliyski | 5,000.47 mi (8,047.48 km) |
| Herndon to Stara Zagora | 5,033.32 mi (8,100.34 km) |
| Herndon to Svilengrad | 5,083.82 mi (8,181.62 km) |
| Herndon to Svishtov | 4,971.68 mi (8,001.15 km) |
| Herndon to Targovishte | 5,036.20 mi (8,104.98 km) |
| Herndon to Teteven | 4,957.13 mi (7,977.74 km) |
| Herndon to Troyan | 4,976.75 mi (8,009.30 km) |
| Herndon to Tryavna | 5,009.04 mi (8,061.27 km) |
| Herndon to Tutrakan | 5,003.66 mi (8,052.61 km) |
| Herndon to Varna | 5,090.35 mi (8,192.12 km) |
