| Riverside to Smolyan | 6,691.00 mi (10,768.12 km) |
| Riverside to Sofia | 6,588.59 mi (10,603.31 km) |
| Riverside to Sopot | 6,629.03 mi (10,668.39 km) |
| Riverside to Sozopol | 6,717.42 mi (10,810.65 km) |
| Riverside to Sredets | 6,709.18 mi (10,797.37 km) |
| Riverside to Stamboliyski | 6,653.99 mi (10,708.56 km) |
| Riverside to Stara Zagora | 6,665.16 mi (10,726.54 km) |
| Riverside to Svilengrad | 6,719.14 mi (10,813.42 km) |
| Riverside to Svishtov | 6,586.87 mi (10,600.55 km) |
| Riverside to Targovishte | 6,639.64 mi (10,685.47 km) |
| Riverside to Teteven | 6,600.62 mi (10,622.67 km) |
| Riverside to Troyan | 6,614.32 mi (10,644.71 km) |
| Riverside to Tryavna | 6,635.43 mi (10,678.69 km) |
| Riverside to Tutrakan | 6,592.28 mi (10,609.25 km) |
| Riverside to Varna | 6,674.08 mi (10,740.89 km) |
