| Castrop-Rauxel to Popovo | 1,045.10 mi (1,681.93 km) |
| Castrop-Rauxel to Provadia | 1,099.24 mi (1,769.05 km) |
| Castrop-Rauxel to Radnevo | 1,081.26 mi (1,740.11 km) |
| Castrop-Rauxel to Radomir | 959.98 mi (1,544.94 km) |
| Castrop-Rauxel to Rakitovo | 1,028.47 mi (1,655.16 km) |
| Castrop-Rauxel to Rakovski | 1,045.74 mi (1,682.96 km) |
| Castrop-Rauxel to Razgrad | 1,048.18 mi (1,686.87 km) |
| Castrop-Rauxel to Razlog | 1,011.55 mi (1,627.93 km) |
| Castrop-Rauxel to Ruse | 1,013.70 mi (1,631.39 km) |
| Castrop-Rauxel to Samokov | 992.09 mi (1,596.61 km) |
| Castrop-Rauxel to Sandanski | 1,021.13 mi (1,643.35 km) |
| Castrop-Rauxel to Sevlievo | 1,016.73 mi (1,636.28 km) |
| Castrop-Rauxel to Shumen | 1,075.30 mi (1,730.52 km) |
| Castrop-Rauxel to Silistra | 1,053.12 mi (1,694.84 km) |
| Castrop-Rauxel to Sliven | 1,078.74 mi (1,736.07 km) |
