| Gastonia to Smolyan | 5,357.11 mi (8,621.43 km) |
| Gastonia to Sofia | 5,254.99 mi (8,457.10 km) |
| Gastonia to Sopot | 5,315.47 mi (8,554.43 km) |
| Gastonia to Sozopol | 5,444.91 mi (8,762.74 km) |
| Gastonia to Sredets | 5,427.60 mi (8,734.88 km) |
| Gastonia to Stamboliyski | 5,327.68 mi (8,574.07 km) |
| Gastonia to Stara Zagora | 5,361.19 mi (8,628.01 km) |
| Gastonia to Svilengrad | 5,411.45 mi (8,708.89 km) |
| Gastonia to Svishtov | 5,300.24 mi (8,529.90 km) |
| Gastonia to Targovishte | 5,364.95 mi (8,634.05 km) |
| Gastonia to Teteven | 5,284.81 mi (8,505.09 km) |
| Gastonia to Troyan | 5,304.58 mi (8,536.90 km) |
| Gastonia to Tryavna | 5,337.16 mi (8,589.33 km) |
| Gastonia to Tutrakan | 5,332.88 mi (8,582.44 km) |
| Gastonia to Varna | 5,419.51 mi (8,721.86 km) |
