| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Siero de la Reina | city | Castilla y Leon | Spain | 42.94 | -4.90 | 4228 | 201 |
| Siete Iglesias | city | Castilla y Leon | Spain | 41.35 | -5.18 | 2509 | 1097 |
| Siete Iglesias de Tormes | city | Castilla y Leon | Spain | 40.74 | -5.58 | 2588 | 1170 |
| Siete Iglesias de Trabancos | city | Castilla y Leon | Spain | 41.35 | -5.18 | 2509 | 1097 |
| Sigeres | city | Castilla y Leon | Spain | 40.80 | -4.93 | 3349 | 875 |
| Siguero | city | Castilla y Leon | Spain | 41.18 | -3.62 | 3674 | 637 |
| Sigueruelo | city | Castilla y Leon | Spain | 41.17 | -3.64 | 3723 | 694 |
| Sigueya | city | Castilla y Leon | Spain | 42.37 | -6.67 | 3349 | 438 |
| Silanes | city | Castilla y Leon | Spain | 42.67 | -3.18 | 2919 | 642 |
| Silván | city | Castilla y Leon | Spain | 42.34 | -6.67 | 4461 | 437 |
| Simancas | city | Castilla y Leon | Spain | 41.59 | -4.83 | 2509 | 55199 |
| Sinlabajos | city | Castilla y Leon | Spain | 41.08 | -4.83 | 2723 | 967 |
| Sinovas | city | Castilla y Leon | Spain | 41.70 | -3.66 | 2723 | 20070 |
| Siones | city | Castilla y Leon | Spain | 43.07 | -3.31 | 1883 | 431 |
| Sitrama de Tera | city | Castilla y Leon | Spain | 42.01 | -5.90 | 2509 | 1727 |
| Sitramina | city | Castilla y Leon | Spain | 42.01 | -5.90 | 2509 | 1727 |
| Siudad-Rodrigo | city | Castilla y Leon | Spain | 40.60 | -6.53 | 2040 | 8606 |