| Merthyr Tudful to Devnya | 1,545.89 mi (2,487.87 km) |
| Merthyr Tudful to Dimitrovgrad | 1,509.69 mi (2,429.61 km) |
| Merthyr Tudful to Dobrich | 1,544.02 mi (2,484.86 km) |
| Merthyr Tudful to Dospat | 1,467.43 mi (2,361.60 km) |
| Merthyr Tudful to Dupnitsa | 1,398.84 mi (2,251.22 km) |
| Merthyr Tudful to Elhovo | 1,545.05 mi (2,486.52 km) |
| Merthyr Tudful to Etropole | 1,411.87 mi (2,272.18 km) |
| Merthyr Tudful to Gabrovo | 1,465.85 mi (2,359.05 km) |
| Merthyr Tudful to Gorna Oryahovitsa | 1,470.74 mi (2,366.93 km) |
| Merthyr Tudful to Gotse Delchev | 1,453.32 mi (2,338.90 km) |
| Merthyr Tudful to Harmanli | 1,526.88 mi (2,457.27 km) |
| Merthyr Tudful to Haskovo | 1,513.10 mi (2,435.10 km) |
| Merthyr Tudful to Ihtiman | 1,420.31 mi (2,285.77 km) |
| Merthyr Tudful to Isperih | 1,496.26 mi (2,408.00 km) |
| Merthyr Tudful to Kardzhali | 1,516.60 mi (2,440.73 km) |
