| Harrow to Popovo | 1,355.64 mi (2,181.69 km) |
| Harrow to Provadia | 1,412.12 mi (2,272.58 km) |
| Harrow to Radnevo | 1,385.24 mi (2,229.33 km) |
| Harrow to Radomir | 1,253.64 mi (2,017.54 km) |
| Harrow to Rakitovo | 1,323.39 mi (2,129.79 km) |
| Harrow to Rakovski | 1,346.17 mi (2,166.46 km) |
| Harrow to Razgrad | 1,360.40 mi (2,189.34 km) |
| Harrow to Razlog | 1,303.01 mi (2,096.99 km) |
| Harrow to Ruse | 1,325.90 mi (2,133.82 km) |
| Harrow to Samokov | 1,287.03 mi (2,071.27 km) |
| Harrow to Sandanski | 1,309.53 mi (2,107.48 km) |
| Harrow to Sevlievo | 1,322.06 mi (2,127.65 km) |
| Harrow to Shumen | 1,387.38 mi (2,232.77 km) |
| Harrow to Silistra | 1,369.78 mi (2,204.45 km) |
| Harrow to Sliven | 1,386.10 mi (2,230.72 km) |
