| Castlebar to Popovo | 1,754.70 mi (2,823.92 km) |
| Castlebar to Provadia | 1,809.87 mi (2,912.71 km) |
| Castlebar to Radnevo | 1,787.22 mi (2,876.25 km) |
| Castlebar to Radomir | 1,658.12 mi (2,668.49 km) |
| Castlebar to Rakitovo | 1,727.73 mi (2,780.51 km) |
| Castlebar to Rakovski | 1,749.23 mi (2,815.12 km) |
| Castlebar to Razgrad | 1,758.51 mi (2,830.05 km) |
| Castlebar to Razlog | 1,707.92 mi (2,748.63 km) |
| Castlebar to Ruse | 1,723.99 mi (2,774.50 km) |
| Castlebar to Samokov | 1,691.32 mi (2,721.91 km) |
| Castlebar to Sandanski | 1,714.85 mi (2,759.78 km) |
| Castlebar to Sevlievo | 1,723.46 mi (2,773.64 km) |
| Castlebar to Shumen | 1,785.60 mi (2,873.65 km) |
| Castlebar to Silistra | 1,764.79 mi (2,840.16 km) |
| Castlebar to Sliven | 1,786.75 mi (2,875.49 km) |
