| Southend to Smolyan | 1,322.34 mi (2,128.09 km) |
| Southend to Sofia | 1,219.31 mi (1,962.29 km) |
| Southend to Sopot | 1,278.66 mi (2,057.80 km) |
| Southend to Sozopol | 1,409.05 mi (2,267.64 km) |
| Southend to Sredets | 1,391.15 mi (2,238.84 km) |
| Southend to Stamboliyski | 1,291.76 mi (2,078.89 km) |
| Southend to Stara Zagora | 1,324.25 mi (2,131.18 km) |
| Southend to Svilengrad | 1,374.69 mi (2,212.35 km) |
| Southend to Svishtov | 1,264.25 mi (2,034.62 km) |
| Southend to Targovishte | 1,329.61 mi (2,139.80 km) |
| Southend to Teteven | 1,248.00 mi (2,008.46 km) |
| Southend to Troyan | 1,267.65 mi (2,040.09 km) |
| Southend to Tryavna | 1,300.29 mi (2,092.62 km) |
| Southend to Tutrakan | 1,300.40 mi (2,092.80 km) |
| Southend to Varna | 1,386.36 mi (2,231.12 km) |
