| Harrow on the Hill to Smolyan | 1,364.48 mi (2,195.92 km) |
| Harrow on the Hill to Sofia | 1,261.65 mi (2,030.43 km) |
| Harrow on the Hill to Sopot | 1,321.46 mi (2,126.68 km) |
| Harrow on the Hill to Sozopol | 1,452.53 mi (2,337.62 km) |
| Harrow on the Hill to Sredets | 1,434.48 mi (2,308.57 km) |
| Harrow on the Hill to Stamboliyski | 1,334.18 mi (2,147.16 km) |
| Harrow on the Hill to Stara Zagora | 1,367.21 mi (2,200.31 km) |
| Harrow on the Hill to Svilengrad | 1,417.45 mi (2,281.17 km) |
| Harrow on the Hill to Svishtov | 1,307.73 mi (2,104.59 km) |
| Harrow on the Hill to Targovishte | 1,373.20 mi (2,209.96 km) |
| Harrow on the Hill to Teteven | 1,290.80 mi (2,077.34 km) |
| Harrow on the Hill to Troyan | 1,310.57 mi (2,109.17 km) |
| Harrow on the Hill to Tryavna | 1,343.43 mi (2,162.04 km) |
| Harrow on the Hill to Tutrakan | 1,344.34 mi (2,163.50 km) |
| Harrow on the Hill to Varna | 1,430.21 mi (2,301.70 km) |
