| Castleford to Karlovo | 1,415.14 mi (2,277.45 km) |
| Castleford to Karnobat | 1,498.91 mi (2,412.26 km) |
| Castleford to Kavarna | 1,516.45 mi (2,440.49 km) |
| Castleford to Kazanlak | 1,438.91 mi (2,315.70 km) |
| Castleford to Knezha | 1,348.70 mi (2,170.53 km) |
| Castleford to Kostinbrod | 1,347.26 mi (2,168.20 km) |
| Castleford to Kozloduy | 1,322.70 mi (2,128.68 km) |
| Castleford to Kyustendil | 1,352.73 mi (2,177.01 km) |
| Castleford to Levski | 1,394.85 mi (2,244.79 km) |
| Castleford to Lom | 1,301.93 mi (2,095.25 km) |
| Castleford to Lovech | 1,389.32 mi (2,235.90 km) |
| Castleford to Lukovit | 1,365.41 mi (2,197.42 km) |
| Castleford to Lyaskovets | 1,429.17 mi (2,300.03 km) |
| Castleford to Mezdra | 1,350.01 mi (2,172.63 km) |
| Castleford to Momchilgrad | 1,490.11 mi (2,398.10 km) |
