| Mason City to Smolyan | 5,427.13 mi (8,734.12 km) |
| Mason City to Sofia | 5,322.84 mi (8,566.28 km) |
| Mason City to Sopot | 5,373.36 mi (8,647.59 km) |
| Mason City to Sozopol | 5,483.00 mi (8,824.04 km) |
| Mason City to Sredets | 5,470.25 mi (8,803.51 km) |
| Mason City to Stamboliyski | 5,392.89 mi (8,679.02 km) |
| Mason City to Stara Zagora | 5,414.71 mi (8,714.14 km) |
| Mason City to Svilengrad | 5,468.04 mi (8,799.97 km) |
| Mason City to Svishtov | 5,342.98 mi (8,598.70 km) |
| Mason City to Targovishte | 5,402.54 mi (8,694.54 km) |
| Mason City to Teteven | 5,343.33 mi (8,599.26 km) |
| Mason City to Troyan | 5,360.13 mi (8,626.30 km) |
| Mason City to Tryavna | 5,387.05 mi (8,669.63 km) |
| Mason City to Tutrakan | 5,361.49 mi (8,628.49 km) |
| Mason City to Varna | 5,447.38 mi (8,766.71 km) |
