| Willowbrook to Smolyan | 6,714.16 mi (10,805.39 km) |
| Willowbrook to Sofia | 6,611.97 mi (10,640.93 km) |
| Willowbrook to Sopot | 6,651.76 mi (10,704.97 km) |
| Willowbrook to Sozopol | 6,738.81 mi (10,845.07 km) |
| Willowbrook to Sredets | 6,730.84 mi (10,832.24 km) |
| Willowbrook to Stamboliyski | 6,677.02 mi (10,745.63 km) |
| Willowbrook to Stara Zagora | 6,687.54 mi (10,762.56 km) |
| Willowbrook to Svilengrad | 6,741.51 mi (10,849.41 km) |
| Willowbrook to Svishtov | 6,608.96 mi (10,636.09 km) |
| Willowbrook to Targovishte | 6,661.27 mi (10,720.28 km) |
| Willowbrook to Teteven | 6,623.48 mi (10,659.46 km) |
| Willowbrook to Troyan | 6,636.98 mi (10,681.18 km) |
| Willowbrook to Tryavna | 6,657.72 mi (10,714.57 km) |
| Willowbrook to Tutrakan | 6,613.60 mi (10,643.57 km) |
| Willowbrook to Varna | 6,695.07 mi (10,774.68 km) |
