| Serris to Popovo | 1,180.34 mi (1,899.57 km) |
| Serris to Provadia | 1,239.36 mi (1,994.56 km) |
| Serris to Radnevo | 1,201.64 mi (1,933.85 km) |
| Serris to Radomir | 1,061.86 mi (1,708.89 km) |
| Serris to Rakitovo | 1,131.73 mi (1,821.34 km) |
| Serris to Rakovski | 1,159.36 mi (1,865.81 km) |
| Serris to Razgrad | 1,187.36 mi (1,910.87 km) |
| Serris to Razlog | 1,108.68 mi (1,784.25 km) |
| Serris to Ruse | 1,153.30 mi (1,856.06 km) |
| Serris to Samokov | 1,095.88 mi (1,763.64 km) |
| Serris to Sandanski | 1,112.70 mi (1,790.72 km) |
| Serris to Sevlievo | 1,140.79 mi (1,835.92 km) |
| Serris to Shumen | 1,213.79 mi (1,953.41 km) |
| Serris to Silistra | 1,203.57 mi (1,936.97 km) |
| Serris to Sliven | 1,206.36 mi (1,941.45 km) |
