| Unterwellenborn to Smolyan | 889.84 mi (1,432.07 km) |
| Unterwellenborn to Sofia | 785.56 mi (1,264.24 km) |
| Unterwellenborn to Sopot | 837.11 mi (1,347.19 km) |
| Unterwellenborn to Sozopol | 956.44 mi (1,539.24 km) |
| Unterwellenborn to Sredets | 940.76 mi (1,514.01 km) |
| Unterwellenborn to Stamboliyski | 855.65 mi (1,377.04 km) |
| Unterwellenborn to Stara Zagora | 879.89 mi (1,416.05 km) |
| Unterwellenborn to Svilengrad | 932.54 mi (1,500.78 km) |
| Unterwellenborn to Svishtov | 812.70 mi (1,307.92 km) |
| Unterwellenborn to Targovishte | 875.91 mi (1,409.64 km) |
| Unterwellenborn to Teteven | 806.82 mi (1,298.45 km) |
| Unterwellenborn to Troyan | 824.41 mi (1,326.75 km) |
| Unterwellenborn to Tryavna | 853.45 mi (1,373.49 km) |
| Unterwellenborn to Tutrakan | 841.96 mi (1,355.00 km) |
| Unterwellenborn to Varna | 928.69 mi (1,494.59 km) |
