| Iowa City to Smolyan | 5,444.97 mi (8,762.83 km) |
| Iowa City to Sofia | 5,340.69 mi (8,595.01 km) |
| Iowa City to Sopot | 5,392.95 mi (8,679.12 km) |
| Iowa City to Sozopol | 5,506.07 mi (8,861.16 km) |
| Iowa City to Sredets | 5,492.55 mi (8,839.41 km) |
| Iowa City to Stamboliyski | 5,411.39 mi (8,708.79 km) |
| Iowa City to Stara Zagora | 5,435.13 mi (8,747.00 km) |
| Iowa City to Svilengrad | 5,488.14 mi (8,832.31 km) |
| Iowa City to Svishtov | 5,364.88 mi (8,633.93 km) |
| Iowa City to Targovishte | 5,425.43 mi (8,731.38 km) |
| Iowa City to Teteven | 5,362.73 mi (8,630.48 km) |
| Iowa City to Troyan | 5,380.06 mi (8,658.36 km) |
| Iowa City to Tryavna | 5,407.96 mi (8,703.26 km) |
| Iowa City to Tutrakan | 5,385.67 mi (8,667.40 km) |
| Iowa City to Varna | 5,471.94 mi (8,806.24 km) |
