| Rheinfelden to Smolyan | 925.79 mi (1,489.91 km) |
| Rheinfelden to Sofia | 826.03 mi (1,329.36 km) |
| Rheinfelden to Sopot | 890.97 mi (1,433.87 km) |
| Rheinfelden to Sozopol | 1,031.65 mi (1,660.28 km) |
| Rheinfelden to Sredets | 1,011.06 mi (1,627.14 km) |
| Rheinfelden to Stamboliyski | 898.75 mi (1,446.39 km) |
| Rheinfelden to Stara Zagora | 938.42 mi (1,510.24 km) |
| Rheinfelden to Svilengrad | 985.50 mi (1,586.02 km) |
| Rheinfelden to Svishtov | 888.83 mi (1,430.44 km) |
| Rheinfelden to Targovishte | 955.66 mi (1,537.98 km) |
| Rheinfelden to Teteven | 860.69 mi (1,385.15 km) |
| Rheinfelden to Troyan | 881.97 mi (1,419.40 km) |
| Rheinfelden to Tryavna | 917.83 mi (1,477.10 km) |
| Rheinfelden to Tutrakan | 935.49 mi (1,505.53 km) |
| Rheinfelden to Varna | 1,017.76 mi (1,637.93 km) |
