| Niederkassel to Karlovo | 1,009.53 mi (1,624.68 km) |
| Niederkassel to Karnobat | 1,095.94 mi (1,763.75 km) |
| Niederkassel to Kavarna | 1,118.25 mi (1,799.65 km) |
| Niederkassel to Kazanlak | 1,033.86 mi (1,663.84 km) |
| Niederkassel to Knezha | 943.80 mi (1,518.90 km) |
| Niederkassel to Kostinbrod | 940.63 mi (1,513.80 km) |
| Niederkassel to Kozloduy | 917.95 mi (1,477.30 km) |
| Niederkassel to Kyustendil | 945.71 mi (1,521.98 km) |
| Niederkassel to Levski | 991.01 mi (1,594.87 km) |
| Niederkassel to Lom | 896.68 mi (1,443.07 km) |
| Niederkassel to Lovech | 984.45 mi (1,584.32 km) |
| Niederkassel to Lukovit | 960.05 mi (1,545.05 km) |
| Niederkassel to Lyaskovets | 1,025.51 mi (1,650.40 km) |
| Niederkassel to Mezdra | 944.11 mi (1,519.40 km) |
| Niederkassel to Momchilgrad | 1,083.67 mi (1,744.00 km) |
