| Alfter to Smolyan | 1,052.25 mi (1,693.43 km) |
| Alfter to Sofia | 948.43 mi (1,526.35 km) |
| Alfter to Sopot | 1,005.41 mi (1,618.06 km) |
| Alfter to Sozopol | 1,132.75 mi (1,822.98 km) |
| Alfter to Sredets | 1,115.45 mi (1,795.14 km) |
| Alfter to Stamboliyski | 1,020.34 mi (1,642.07 km) |
| Alfter to Stara Zagora | 1,050.24 mi (1,690.19 km) |
| Alfter to Svilengrad | 1,101.48 mi (1,772.66 km) |
| Alfter to Svishtov | 988.04 mi (1,590.10 km) |
| Alfter to Targovishte | 1,052.93 mi (1,694.52 km) |
| Alfter to Teteven | 974.79 mi (1,568.77 km) |
| Alfter to Troyan | 993.85 mi (1,599.45 km) |
| Alfter to Tryavna | 1,025.47 mi (1,650.34 km) |
| Alfter to Tutrakan | 1,022.59 mi (1,645.70 km) |
| Alfter to Varna | 1,108.78 mi (1,784.40 km) |
