| Letterkenny to Karlovo | 1,685.32 mi (2,712.26 km) |
| Letterkenny to Karnobat | 1,768.99 mi (2,846.91 km) |
| Letterkenny to Kavarna | 1,785.68 mi (2,873.78 km) |
| Letterkenny to Kazanlak | 1,709.11 mi (2,750.55 km) |
| Letterkenny to Knezha | 1,618.91 mi (2,605.39 km) |
| Letterkenny to Kostinbrod | 1,617.17 mi (2,602.59 km) |
| Letterkenny to Kozloduy | 1,592.91 mi (2,563.54 km) |
| Letterkenny to Kyustendil | 1,622.12 mi (2,610.55 km) |
| Letterkenny to Levski | 1,665.02 mi (2,679.59 km) |
| Letterkenny to Lom | 1,572.13 mi (2,530.09 km) |
| Letterkenny to Lovech | 1,659.53 mi (2,670.76 km) |
| Letterkenny to Lukovit | 1,635.60 mi (2,632.25 km) |
| Letterkenny to Lyaskovets | 1,699.33 mi (2,734.81 km) |
| Letterkenny to Mezdra | 1,620.15 mi (2,607.38 km) |
| Letterkenny to Momchilgrad | 1,760.11 mi (2,832.63 km) |
