| Castleton to Popovo | 1,467.24 mi (2,361.29 km) |
| Castleton to Provadia | 1,521.57 mi (2,448.74 km) |
| Castleton to Radnevo | 1,502.09 mi (2,417.38 km) |
| Castleton to Radomir | 1,376.87 mi (2,215.86 km) |
| Castleton to Rakitovo | 1,446.04 mi (2,327.18 km) |
| Castleton to Rakovski | 1,465.44 mi (2,358.39 km) |
| Castleton to Razgrad | 1,470.47 mi (2,366.49 km) |
| Castleton to Razlog | 1,427.57 mi (2,297.45 km) |
| Castleton to Ruse | 1,435.98 mi (2,310.99 km) |
| Castleton to Samokov | 1,409.59 mi (2,268.52 km) |
| Castleton to Sandanski | 1,435.72 mi (2,310.57 km) |
| Castleton to Sevlievo | 1,437.85 mi (2,314.00 km) |
| Castleton to Shumen | 1,497.59 mi (2,410.13 km) |
| Castleton to Silistra | 1,475.31 mi (2,374.29 km) |
| Castleton to Sliven | 1,500.38 mi (2,414.63 km) |
