| Siegburg to Smolyan | 1,047.19 mi (1,685.29 km) |
| Siegburg to Sofia | 943.29 mi (1,518.08 km) |
| Siegburg to Sopot | 999.90 mi (1,609.19 km) |
| Siegburg to Sozopol | 1,126.64 mi (1,813.14 km) |
| Siegburg to Sredets | 1,109.47 mi (1,785.51 km) |
| Siegburg to Stamboliyski | 1,015.10 mi (1,633.64 km) |
| Siegburg to Stara Zagora | 1,044.58 mi (1,681.09 km) |
| Siegburg to Svilengrad | 1,095.95 mi (1,763.77 km) |
| Siegburg to Svishtov | 981.97 mi (1,580.33 km) |
| Siegburg to Targovishte | 1,046.73 mi (1,684.56 km) |
| Siegburg to Teteven | 969.29 mi (1,559.92 km) |
| Siegburg to Troyan | 988.25 mi (1,590.43 km) |
| Siegburg to Tryavna | 1,019.68 mi (1,641.01 km) |
| Siegburg to Tutrakan | 1,016.07 mi (1,635.21 km) |
| Siegburg to Varna | 1,102.32 mi (1,774.02 km) |
