| Birchington to Smolyan | 1,294.11 mi (2,082.66 km) |
| Birchington to Sofia | 1,191.10 mi (1,916.89 km) |
| Birchington to Sopot | 1,250.53 mi (2,012.53 km) |
| Birchington to Sozopol | 1,381.12 mi (2,222.71 km) |
| Birchington to Sredets | 1,363.17 mi (2,193.81 km) |
| Birchington to Stamboliyski | 1,263.57 mi (2,033.51 km) |
| Birchington to Stara Zagora | 1,296.16 mi (2,085.97 km) |
| Birchington to Svilengrad | 1,346.55 mi (2,167.06 km) |
| Birchington to Svishtov | 1,236.33 mi (1,989.68 km) |
| Birchington to Targovishte | 1,301.74 mi (2,094.95 km) |
| Birchington to Teteven | 1,219.87 mi (1,963.18 km) |
| Birchington to Troyan | 1,239.55 mi (1,994.86 km) |
| Birchington to Tryavna | 1,272.25 mi (2,047.49 km) |
| Birchington to Tutrakan | 1,272.72 mi (2,048.25 km) |
| Birchington to Varna | 1,358.62 mi (2,186.49 km) |
