| Boerne to Smolyan | 6,329.04 mi (10,185.61 km) |
| Boerne to Sofia | 6,225.08 mi (10,018.29 km) |
| Boerne to Sopot | 6,280.08 mi (10,106.81 km) |
| Boerne to Sozopol | 6,398.28 mi (10,297.04 km) |
| Boerne to Sredets | 6,383.68 mi (10,273.53 km) |
| Boerne to Stamboliyski | 6,296.66 mi (10,133.49 km) |
| Boerne to Stara Zagora | 6,323.47 mi (10,176.64 km) |
| Boerne to Svilengrad | 6,375.84 mi (10,260.92 km) |
| Boerne to Svishtov | 6,255.65 mi (10,067.50 km) |
| Boerne to Targovishte | 6,317.56 mi (10,167.13 km) |
| Boerne to Teteven | 6,249.62 mi (10,057.78 km) |
| Boerne to Troyan | 6,267.74 mi (10,086.95 km) |
| Boerne to Tryavna | 6,297.12 mi (10,134.24 km) |
| Boerne to Tutrakan | 6,279.72 mi (10,106.24 km) |
| Boerne to Varna | 6,366.36 mi (10,245.67 km) |
