| Difficult Run to Sesena | 3,807.24 mi (6,127.16 km) |
| Difficult Run to Sestao | 3,751.44 mi (6,037.36 km) |
| Difficult Run to Sevilla | 3,778.33 mi (6,080.63 km) |
| Difficult Run to Sevilla La Nueva | 3,784.41 mi (6,090.43 km) |
| Difficult Run to Silla | 3,987.05 mi (6,416.53 km) |
| Difficult Run to Silleda | 3,521.45 mi (5,667.22 km) |
| Difficult Run to Sitges | 4,034.62 mi (6,493.09 km) |
| Difficult Run to Socuellamos | 3,874.38 mi (6,235.21 km) |
| Difficult Run to Soller | 4,122.30 mi (6,634.20 km) |
| Difficult Run to Solsona | 3,998.36 mi (6,434.73 km) |
| Difficult Run to Son Servera | 4,158.07 mi (6,691.77 km) |
| Difficult Run to Sonseca | 3,806.65 mi (6,126.22 km) |
| Difficult Run to Sopelana | 3,750.79 mi (6,036.31 km) |
| Difficult Run to Soria | 3,818.83 mi (6,145.81 km) |
| Difficult Run to Suances | 3,699.71 mi (5,954.11 km) |
