| Siegen to Smolyan | 1,019.98 mi (1,641.49 km) |
| Siegen to Sofia | 915.89 mi (1,473.98 km) |
| Siegen to Sopot | 971.42 mi (1,563.35 km) |
| Siegen to Sozopol | 1,096.48 mi (1,764.62 km) |
| Siegen to Sredets | 1,079.67 mi (1,737.56 km) |
| Siegen to Stamboliyski | 987.39 mi (1,589.05 km) |
| Siegen to Stara Zagora | 1,015.70 mi (1,634.61 km) |
| Siegen to Svilengrad | 1,067.40 mi (1,717.82 km) |
| Siegen to Svishtov | 951.96 mi (1,532.04 km) |
| Siegen to Targovishte | 1,016.39 mi (1,635.72 km) |
| Siegen to Teteven | 940.85 mi (1,514.16 km) |
| Siegen to Troyan | 959.52 mi (1,544.19 km) |
| Siegen to Tryavna | 990.42 mi (1,593.92 km) |
| Siegen to Tutrakan | 984.88 mi (1,585.01 km) |
| Siegen to Varna | 1,071.30 mi (1,724.09 km) |
