| Welby to Smolyan | 5,986.26 mi (9,633.95 km) |
| Welby to Sofia | 5,882.44 mi (9,466.88 km) |
| Welby to Sopot | 5,928.39 mi (9,540.81 km) |
| Welby to Sozopol | 6,028.47 mi (9,701.88 km) |
| Welby to Sredets | 6,017.78 mi (9,684.68 km) |
| Welby to Stamboliyski | 5,950.57 mi (9,576.52 km) |
| Welby to Stara Zagora | 5,967.44 mi (9,603.67 km) |
| Welby to Svilengrad | 6,021.31 mi (9,690.36 km) |
| Welby to Svishtov | 5,892.29 mi (9,482.73 km) |
| Welby to Targovishte | 5,948.90 mi (9,573.83 km) |
| Welby to Teteven | 5,899.00 mi (9,493.52 km) |
| Welby to Troyan | 5,914.40 mi (9,518.31 km) |
| Welby to Tryavna | 5,938.68 mi (9,557.38 km) |
| Welby to Tutrakan | 5,904.68 mi (9,502.66 km) |
| Welby to Varna | 5,989.04 mi (9,638.42 km) |
