| Bostonia to Smolyan | 6,747.43 mi (10,858.94 km) |
| Bostonia to Sofia | 6,644.74 mi (10,693.67 km) |
| Bostonia to Sopot | 6,686.06 mi (10,760.18 km) |
| Bostonia to Sozopol | 6,776.24 mi (10,905.30 km) |
| Bostonia to Sredets | 6,767.64 mi (10,891.46 km) |
| Bostonia to Stamboliyski | 6,710.61 mi (10,799.68 km) |
| Bostonia to Stara Zagora | 6,722.66 mi (10,819.08 km) |
| Bostonia to Svilengrad | 6,776.66 mi (10,905.98 km) |
| Bostonia to Svishtov | 6,644.80 mi (10,693.77 km) |
| Bostonia to Targovishte | 6,698.15 mi (10,779.63 km) |
| Bostonia to Teteven | 6,657.49 mi (10,714.19 km) |
| Bostonia to Troyan | 6,671.45 mi (10,736.67 km) |
| Bostonia to Tryavna | 6,693.06 mi (10,771.44 km) |
| Bostonia to Tutrakan | 6,651.21 mi (10,704.08 km) |
| Bostonia to Varna | 6,733.41 mi (10,836.38 km) |
