| Douglas to Smolyan | 1,703.74 mi (2,741.90 km) |
| Douglas to Sofia | 1,601.91 mi (2,578.03 km) |
| Douglas to Sopot | 1,663.51 mi (2,677.16 km) |
| Douglas to Sozopol | 1,797.09 mi (2,892.13 km) |
| Douglas to Sredets | 1,778.50 mi (2,862.22 km) |
| Douglas to Stamboliyski | 1,674.66 mi (2,695.11 km) |
| Douglas to Stara Zagora | 1,709.83 mi (2,751.70 km) |
| Douglas to Svilengrad | 1,759.26 mi (2,831.25 km) |
| Douglas to Svishtov | 1,652.37 mi (2,659.24 km) |
| Douglas to Targovishte | 1,718.20 mi (2,765.18 km) |
| Douglas to Teteven | 1,632.89 mi (2,627.88 km) |
| Douglas to Troyan | 1,653.12 mi (2,660.45 km) |
| Douglas to Tryavna | 1,686.80 mi (2,714.64 km) |
| Douglas to Tutrakan | 1,690.44 mi (2,720.51 km) |
| Douglas to Varna | 1,776.03 mi (2,858.25 km) |
