| Willebroek to Sofia | 1,061.10 mi (1,707.68 km) |
| Willebroek to Sopot | 1,119.39 mi (1,801.48 km) |
| Willebroek to Sozopol | 1,248.45 mi (2,009.19 km) |
| Willebroek to Sredets | 1,230.81 mi (1,980.79 km) |
| Willebroek to Stamboliyski | 1,133.33 mi (1,823.92 km) |
| Willebroek to Stara Zagora | 1,164.65 mi (1,874.32 km) |
| Willebroek to Svilengrad | 1,215.46 mi (1,956.10 km) |
| Willebroek to Svishtov | 1,103.68 mi (1,776.20 km) |
| Willebroek to Targovishte | 1,168.85 mi (1,881.08 km) |
| Willebroek to Teteven | 1,088.73 mi (1,752.15 km) |
| Willebroek to Troyan | 1,108.13 mi (1,783.36 km) |
| Willebroek to Tryavna | 1,140.32 mi (1,835.17 km) |
| Willebroek to Tutrakan | 1,139.20 mi (1,833.36 km) |
| Willebroek to Varna | 1,225.24 mi (1,971.83 km) |
| Willebroek to Veliki Preslav | 1,181.78 mi (1,901.89 km) |
