| Birsfelden to Devnya | 1,009.83 mi (1,625.17 km) |
| Birsfelden to Dimitrovgrad | 956.95 mi (1,540.06 km) |
| Birsfelden to Dobrich | 1,012.47 mi (1,629.41 km) |
| Birsfelden to Dospat | 907.82 mi (1,461.00 km) |
| Birsfelden to Dupnitsa | 839.68 mi (1,351.33 km) |
| Birsfelden to Elhovo | 996.41 mi (1,603.56 km) |
| Birsfelden to Etropole | 859.40 mi (1,383.07 km) |
| Birsfelden to Gabrovo | 918.34 mi (1,477.93 km) |
| Birsfelden to Gorna Oryahovitsa | 926.87 mi (1,491.66 km) |
| Birsfelden to Gotse Delchev | 892.08 mi (1,435.67 km) |
| Birsfelden to Harmanli | 974.33 mi (1,568.03 km) |
| Birsfelden to Haskovo | 959.47 mi (1,544.11 km) |
| Birsfelden to Ihtiman | 864.40 mi (1,391.12 km) |
| Birsfelden to Isperih | 962.35 mi (1,548.75 km) |
| Birsfelden to Kardzhali | 960.54 mi (1,545.84 km) |
