| Caerphilly to Smolyan | 1,482.18 mi (2,385.34 km) |
| Caerphilly to Sofia | 1,379.89 mi (2,220.71 km) |
| Caerphilly to Sopot | 1,440.75 mi (2,318.66 km) |
| Caerphilly to Sozopol | 1,573.40 mi (2,532.14 km) |
| Caerphilly to Sredets | 1,555.00 mi (2,502.53 km) |
| Caerphilly to Stamboliyski | 1,452.56 mi (2,337.67 km) |
| Caerphilly to Stara Zagora | 1,486.85 mi (2,392.85 km) |
| Caerphilly to Svilengrad | 1,536.62 mi (2,472.94 km) |
| Caerphilly to Svishtov | 1,428.65 mi (2,299.19 km) |
| Caerphilly to Targovishte | 1,494.37 mi (2,404.95 km) |
| Caerphilly to Teteven | 1,410.11 mi (2,269.35 km) |
| Caerphilly to Troyan | 1,430.16 mi (2,301.62 km) |
| Caerphilly to Tryavna | 1,463.53 mi (2,355.32 km) |
| Caerphilly to Tutrakan | 1,466.32 mi (2,359.81 km) |
| Caerphilly to Varna | 1,551.97 mi (2,497.65 km) |
