| Donegal to Karlovo | 1,694.40 mi (2,726.88 km) |
| Donegal to Karnobat | 1,779.11 mi (2,863.20 km) |
| Donegal to Kavarna | 1,796.99 mi (2,891.97 km) |
| Donegal to Kazanlak | 1,718.47 mi (2,765.61 km) |
| Donegal to Knezha | 1,628.32 mi (2,620.52 km) |
| Donegal to Kostinbrod | 1,625.58 mi (2,616.12 km) |
| Donegal to Kozloduy | 1,602.37 mi (2,578.77 km) |
| Donegal to Kyustendil | 1,629.81 mi (2,622.93 km) |
| Donegal to Levski | 1,674.83 mi (2,695.38 km) |
| Donegal to Lom | 1,581.38 mi (2,544.98 km) |
| Donegal to Lovech | 1,668.96 mi (2,685.92 km) |
| Donegal to Lukovit | 1,644.81 mi (2,647.06 km) |
| Donegal to Lyaskovets | 1,709.21 mi (2,750.70 km) |
| Donegal to Mezdra | 1,629.07 mi (2,621.74 km) |
| Donegal to Momchilgrad | 1,768.67 mi (2,846.40 km) |
