| Donegal to Popovo | 1,718.35 mi (2,765.41 km) |
| Donegal to Provadia | 1,772.48 mi (2,852.53 km) |
| Donegal to Radnevo | 1,753.35 mi (2,821.74 km) |
| Donegal to Radomir | 1,627.60 mi (2,619.38 km) |
| Donegal to Rakitovo | 1,696.88 mi (2,730.87 km) |
| Donegal to Rakovski | 1,716.60 mi (2,762.60 km) |
| Donegal to Razgrad | 1,721.46 mi (2,770.41 km) |
| Donegal to Razlog | 1,678.11 mi (2,700.66 km) |
| Donegal to Ruse | 1,686.98 mi (2,714.94 km) |
| Donegal to Samokov | 1,660.43 mi (2,672.21 km) |
| Donegal to Sandanski | 1,685.96 mi (2,713.29 km) |
| Donegal to Sevlievo | 1,689.11 mi (2,718.37 km) |
| Donegal to Shumen | 1,748.58 mi (2,814.06 km) |
| Donegal to Silistra | 1,725.73 mi (2,777.29 km) |
| Donegal to Sliven | 1,751.62 mi (2,818.96 km) |
