| Waltham to Smolyan | 4,631.32 mi (7,453.38 km) |
| Waltham to Sofia | 4,528.99 mi (7,288.70 km) |
| Waltham to Sopot | 4,589.11 mi (7,385.46 km) |
| Waltham to Sozopol | 4,718.10 mi (7,593.04 km) |
| Waltham to Sredets | 4,700.87 mi (7,565.32 km) |
| Waltham to Stamboliyski | 4,601.62 mi (7,405.60 km) |
| Waltham to Stara Zagora | 4,634.72 mi (7,458.86 km) |
| Waltham to Svilengrad | 4,685.12 mi (7,539.97 km) |
| Waltham to Svishtov | 4,573.44 mi (7,360.25 km) |
| Waltham to Targovishte | 4,638.09 mi (7,464.29 km) |
| Waltham to Teteven | 4,558.45 mi (7,336.12 km) |
| Waltham to Troyan | 4,578.13 mi (7,367.79 km) |
| Waltham to Tryavna | 4,610.56 mi (7,419.97 km) |
| Waltham to Tutrakan | 4,605.93 mi (7,412.52 km) |
| Waltham to Varna | 4,692.56 mi (7,551.95 km) |
