| Palo Alto to Smolyan | 6,593.11 mi (10,610.59 km) |
| Palo Alto to Sofia | 6,492.82 mi (10,449.19 km) |
| Palo Alto to Sopot | 6,527.90 mi (10,505.64 km) |
| Palo Alto to Sozopol | 6,605.35 mi (10,630.29 km) |
| Palo Alto to Sredets | 6,599.26 mi (10,620.48 km) |
| Palo Alto to Stamboliyski | 6,555.19 mi (10,549.55 km) |
| Palo Alto to Stara Zagora | 6,561.12 mi (10,559.11 km) |
| Palo Alto to Svilengrad | 6,614.78 mi (10,645.45 km) |
| Palo Alto to Svishtov | 6,480.70 mi (10,429.68 km) |
| Palo Alto to Targovishte | 6,529.72 mi (10,508.57 km) |
| Palo Alto to Teteven | 6,500.60 mi (10,461.70 km) |
| Palo Alto to Troyan | 6,512.65 mi (10,481.10 km) |
| Palo Alto to Tryavna | 6,530.77 mi (10,510.26 km) |
| Palo Alto to Tutrakan | 6,480.08 mi (10,428.68 km) |
| Palo Alto to Varna | 6,559.07 mi (10,555.80 km) |
