| Prospect Heights to Smolyan | 5,293.58 mi (8,519.19 km) |
| Prospect Heights to Sofia | 5,189.41 mi (8,351.55 km) |
| Prospect Heights to Sopot | 5,243.11 mi (8,437.96 km) |
| Prospect Heights to Sozopol | 5,359.15 mi (8,624.72 km) |
| Prospect Heights to Sredets | 5,344.98 mi (8,601.91 km) |
| Prospect Heights to Stamboliyski | 5,260.58 mi (8,466.09 km) |
| Prospect Heights to Stara Zagora | 5,285.95 mi (8,506.92 km) |
| Prospect Heights to Svilengrad | 5,338.63 mi (8,591.70 km) |
| Prospect Heights to Svishtov | 5,217.06 mi (8,396.04 km) |
| Prospect Heights to Targovishte | 5,278.44 mi (8,494.83 km) |
| Prospect Heights to Teteven | 5,212.74 mi (8,389.10 km) |
| Prospect Heights to Troyan | 5,230.50 mi (8,417.68 km) |
| Prospect Heights to Tryavna | 5,259.23 mi (8,463.91 km) |
| Prospect Heights to Tutrakan | 5,239.87 mi (8,432.76 km) |
| Prospect Heights to Varna | 5,326.41 mi (8,572.02 km) |
