| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Siabal | city | Galicia | Spain | 42.29 | -7.77 | 1669 | 8689 |
| Siabo | city | Galicia | Spain | 42.80 | -8.94 | 26 | 12287 |
| Siador | city | Galicia | Spain | 42.68 | -8.26 | 1998 | 6983 |
| Siavo | city | Galicia | Spain | 42.80 | -8.94 | 26 | 12287 |
| Sidamon | city | Cataluna | Spain | 41.63 | 0.83 | 830 | 11347 |
| Sidamunt | city | Cataluna | Spain | 41.63 | 0.83 | 830 | 11347 |
| Sieh.o | city | Asturias | Spain | 43.33 | -4.59 | 177 | 2218 |
| Sieiro | city | Galicia | Spain | 43.57 | -7.27 | 78 | 6037 |
| Siejo | city | Asturias | Spain | 43.33 | -4.59 | 177 | 2218 |
| Sienes | city | Castilla-La Mancha | Spain | 41.20 | -2.65 | 3625 | 591 |
| Sienra | city | Asturias | Spain | 43.36 | -5.46 | 830 | 4070 |
| Sieres | city | Asturias | Spain | 43.39 | -5.32 | 1164 | 3690 |
| Siero | city | Asturias | Spain | 43.08 | -6.48 | 2509 | 1490 |
| Siero | city | Asturias | Spain | 43.39 | -5.66 | 830 | 24131 |
| Siero de la Reina | city | Castilla y Leon | Spain | 42.94 | -4.90 | 4228 | 201 |
| Sierra | city | Cantabria | Spain | 43.39 | -4.24 | 246 | 3669 |
| Sierra | city | Asturias | Spain | 43.37 | -5.55 | 967 | 8904 |
| Sierra | city | Asturias | Spain | 43.31 | -5.37 | 1669 | 3044 |
| Sierra | city | Euskadi | Spain | 43.21 | -3.37 | 853 | 2052 |
| Sierra | city | Galicia | Spain | 42.76 | -7.05 | 3349 | 1190 |
| Sierra | city | Castilla-La Mancha | Spain | 38.56 | -1.66 | 1778 | 9110 |
| Sierra | city | Andalucia | Spain | 37.04 | -3.56 | 5029 | 12949 |
| Sierra | city | Asturias | Spain | 43.21 | -6.44 | 2660 | 1490 |
| Sierra Ahillos | city | Andalucia | Spain | 37.61 | -4.03 | 3349 | 4024 |
| Sierra Alhamilla | city | Andalucia | Spain | 36.97 | -2.40 | 2509 | 4794 |
| Sierra Gorda | city | Extremadura | Spain | 38.43 | -6.54 | 1738 | 1858 |
| Sierra Santa Olalla | city | Extremadura | Spain | 40.14 | -6.78 | 2063 | 1278 |
| Sierra de Estronad | city | Aragon | Spain | 42.27 | -0.79 | 1994 | 434 |
| Sierra de Fuentes | city | Extremadura | Spain | 39.44 | -6.27 | 1669 | 8593 |
| Sierra de Ibio | city | Cantabria | Spain | 43.32 | -4.16 | 830 | 9743 |
| Sierra de Luna | city | Aragon | Spain | 42.05 | -0.91 | 1669 | 570 |
| Sierra de Outes | city | Galicia | Spain | 42.84 | -8.91 | 203 | 10904 |
| Sierra de Yeguas | city | Andalucia | Spain | 37.12 | -4.87 | 1669 | 3949 |
| Sierra de los Blancos | city | Aragon | Spain | 42.19 | -0.77 | 1669 | 461 |
| Sierra-Engarcerán | city | Comunitat Valenciana | Spain | 40.27 | -0.02 | 2588 | 1176 |
| Sierrapando | city | Cantabria | Spain | 43.34 | -4.04 | 830 | 64717 |
| Sierrezuela | city | Andalucia | Spain | 37.54 | -3.91 | 3349 | 4227 |
| Sierro | city | Andalucia | Spain | 37.32 | -2.40 | 2509 | 2143 |
| Sieso de Huesca | city | Aragon | Spain | 42.16 | -0.15 | 1788 | 279 |
| Sieso de Jaca | city | Aragon | Spain | 42.44 | -0.52 | 2805 | 254 |
| Sieste | city | Aragon | Spain | 42.43 | 0.07 | 1952 | 622 |
| Siete Aguas | city | Comunitat Valenciana | Spain | 39.47 | -0.92 | 2509 | 1058 |
| Siete Casas | city | Comunitat Valenciana | Spain | 38.14 | -1.02 | 255 | 9173 |
| 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 |
| Sietecoros | city | Galicia | Spain | 42.67 | -8.67 | 367 | 11815 |
| Sieteiglesias | city | Galicia | Spain | 42.80 | -7.82 | 1843 | 3219 |
| Sieteiglesias | city | Madrid | Spain | 40.91 | -3.58 | 2929 | 1541 |
| Sietemo | city | Aragon | Spain | 42.12 | -0.28 | 1669 | 740 |
| Sietes | city | Asturias | Spain | 43.43 | -5.37 | 830 | 2903 |
| Sigeres | city | Castilla y Leon | Spain | 40.80 | -4.93 | 3349 | 875 |
| Signada | city | Galicia | Spain | 43.01 | -7.02 | 2011 | 804 |
| Sigras | city | Galicia | Spain | 43.29 | -8.37 | 98 | 53563 |
| Sigrás de Abajo | city | Galicia | Spain | 43.28 | -8.37 | 98 | 50661 |
| Sigrás de Arriba | city | Galicia | Spain | 43.28 | -8.37 | 98 | 50661 |
| Siguees | city | Aragon | Spain | 42.63 | -1.01 | 2060 | 249 |
| Siguensa | city | Castilla-La Mancha | Spain | 41.07 | -2.64 | 3369 | 1188 |
| Siguenza | city | Castilla-La Mancha | Spain | 41.07 | -2.64 | 3369 | 1188 |
| 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 |
| Sigvenco | city | Castilla-La Mancha | Spain | 41.07 | -2.64 | 3369 | 1188 |
| Sigüeiro | city | Galicia | Spain | 42.97 | -8.45 | 830 | 13160 |
| Sigüés | city | Aragon | Spain | 42.63 | -1.01 | 2060 | 249 |
| Silanes | city | Castilla y Leon | Spain | 42.67 | -3.18 | 2919 | 642 |
| Sileras | city | Andalucia | Spain | 37.46 | -4.07 | 2887 | 3170 |
| Siles | city | Andalucia | Spain | 38.39 | -2.58 | 3349 | 1230 |
| Silillos | city | Andalucia | Spain | 37.69 | -5.13 | 830 | 11221 |
| Silim | city | Comunitat Valenciana | Spain | 38.50 | -0.54 | 1669 | 7309 |
| Silio | city | Cantabria | Spain | 43.15 | -4.02 | 1141 | 2077 |
| Silla | city | Comunitat Valenciana | Spain | 39.37 | -0.42 | 26 | 123087 |
| Sillar Alta | city | Andalucia | Spain | 37.34 | -3.41 | 4399 | 1848 |
| Sillar Baja | city | Andalucia | Spain | 37.35 | -3.36 | 4189 | 1928 |
| Silleda | city | Galicia | Spain | 42.70 | -8.25 | 1669 | 7193 |
| Sillede | city | Galicia | Spain | 42.70 | -8.25 | 1669 | 7193 |
| Sillero | city | Andalucia | Spain | 38.10 | -3.02 | 1669 | 5108 |
| Sillobre | city | Galicia | Spain | 43.48 | -8.13 | 830 | 25274 |
| Silos | city | Canarias | Spain | 28.37 | -16.78 | 830 | 10850 |
| Sils | city | Cataluna | Spain | 41.81 | 2.75 | 229 | 8420 |
| Silva | city | Asturias | Spain | 43.27 | -6.41 | 2053 | 2966 |
| Silva | city | Galicia | Spain | 43.15 | -7.35 | 1669 | 1505 |
| Silva | city | Galicia | Spain | 42.75 | -8.94 | 830 | 10317 |
| Silva | city | Galicia | Spain | 41.94 | -7.22 | 2509 | 1433 |
| Silvacha | city | Galicia | Spain | 43.18 | -7.13 | 2578 | 1043 |
| Silvadrosa | city | Galicia | Spain | 43.11 | -7.21 | 1814 | 1044 |
| Silvallana | city | Asturias | Spain | 43.50 | -7.01 | 830 | 6934 |
| Silvallana | city | Asturias | Spain | 43.43 | -6.51 | 1056 | 2358 |
| Silvallana | city | Asturias | Spain | 43.15 | -6.93 | 3349 | 787 |
| Silvamayor | city | Asturias | Spain | 43.52 | -6.39 | 1669 | 3139 |
| Silvarredonda | city | Galicia | Spain | 43.20 | -8.87 | 1020 | 5024 |
| Silvarrey | city | Galicia | Spain | 43.08 | -7.58 | 1669 | 16365 |
| Silvela | city | Galicia | Spain | 43.04 | -7.90 | 2509 | 1563 |
| Silvela | city | Galicia | Spain | 42.74 | -7.07 | 3349 | 1312 |
| Silves | city | Aragon | Spain | 42.45 | 0.04 | 2509 | 465 |
| Silviella | city | Asturias | Spain | 43.44 | -4.97 | 269 | 1912 |
| Silvon | city | Asturias | Spain | 43.38 | -6.82 | 849 | 1311 |
| Silvosa | city | Galicia | Spain | 42.83 | -8.99 | 954 | 4970 |
| Silvota | city | Asturias | Spain | 43.42 | -5.81 | 830 | 34304 |
| Silvouta | city | Galicia | Spain | 42.91 | -6.99 | 2509 | 745 |
| Silván | city | Castilla y Leon | Spain | 42.34 | -6.67 | 4461 | 437 |
| Silán | city | Galicia | Spain | 43.52 | -7.58 | 2509 | 889 |
| Simancas | city | Castilla y Leon | Spain | 41.59 | -4.83 | 2509 | 55199 |
| Simat de Valldigna | city | Comunitat Valenciana | Spain | 39.04 | -0.31 | 830 | 10701 |
| Simat de la Valldigna | city | Comunitat Valenciana | Spain | 39.04 | -0.31 | 830 | 10701 |
| Simes | city | Galicia | Spain | 42.43 | -8.77 | 1003 | 19329 |
| Sin | city | Aragon | Spain | 42.58 | 0.28 | 4189 | 274 |
| Sinagoga | city | Galicia | Spain | 43.01 | -9.19 | 830 | 6826 |
| Sinarcas | city | Comunitat Valenciana | Spain | 39.73 | -1.23 | 3349 | 1104 |
| Sinariega | city | Asturias | Spain | 43.42 | -5.14 | 830 | 5715 |
| Sinarques | city | Comunitat Valenciana | Spain | 39.73 | -1.23 | 3349 | 1104 |
| Sinde | city | Galicia | Spain | 43.21 | -8.94 | 288 | 4847 |
| Sindran | city | Galicia | Spain | 42.52 | -7.42 | 1669 | 4519 |
| Sines | city | Galicia | Spain | 42.43 | -8.77 | 1003 | 19329 |
| Sineu | city | Illes Balears | Spain | 39.64 | 3.01 | 830 | 5009 |
| Singla | city | Asturias | Spain | 43.44 | -5.44 | 1115 | 5252 |
| Singla | city | Murcia | Spain | 38.02 | -1.94 | 2624 | 1192 |
| Singra | city | Aragon | Spain | 40.66 | -1.31 | 3349 | 415 |
| Sinlabajos | city | Castilla y Leon | Spain | 41.08 | -4.83 | 2723 | 967 |
| Sinllán | city | Galicia | Spain | 42.77 | -7.12 | 3349 | 1381 |
| Sinovas | city | Castilla y Leon | Spain | 41.70 | -3.66 | 2723 | 20070 |
| Sint-Djåke-el-Galice | city | Galicia | Spain | 42.88 | -8.54 | 830 | 52656 |
| Sinues | city | Aragon | Spain | 42.65 | -0.65 | 3349 | 588 |
| Siones | city | Castilla y Leon | Spain | 43.07 | -3.31 | 1883 | 431 |
| Sipán | city | Aragon | Spain | 42.18 | -0.27 | 1922 | 325 |
| Siresa | city | Aragon | Spain | 42.76 | -0.75 | 3369 | 405 |
| Sirgal | city | Galicia | Spain | 42.79 | -7.82 | 1742 | 3144 |
| Sirgueiros | city | Galicia | Spain | 42.67 | -7.38 | 2070 | 1364 |
| Sirigal | city | Galicia | Spain | 42.79 | -7.82 | 1742 | 3144 |
| Siruela | city | Extremadura | Spain | 38.98 | -5.05 | 1765 | 1107 |
| Sirviella | city | Asturias | Spain | 43.34 | -4.98 | 830 | 1260 |
| Sirvián | city | Galicia | Spain | 42.93 | -7.72 | 1738 | 3928 |
| Sisamon | city | Aragon | Spain | 41.17 | -2.00 | 3349 | 322 |
| Sisante | city | Castilla-La Mancha | Spain | 39.41 | -2.20 | 2509 | 1183 |
| Siscar | city | Murcia | Spain | 38.07 | -1.02 | 36 | 36687 |
| Sismundi | city | Galicia | Spain | 43.71 | -7.87 | 0 | 7404 |
| Sisoy | city | Galicia | Spain | 43.16 | -7.58 | 1669 | 4491 |
| Sistallo | city | Galicia | Spain | 43.25 | -7.57 | 1669 | 2611 |
| Sisterna | city | Asturias | Spain | 42.96 | -6.67 | 3349 | 998 |
| Sistierna | city | Asturias | Spain | 42.96 | -6.67 | 3349 | 998 |
| Sistin | city | Galicia | Spain | 42.34 | -7.48 | 2700 | 1428 |
| Sisto | city | Galicia | Spain | 43.14 | -8.87 | 830 | 3729 |
| Sisto | city | Galicia | Spain | 42.63 | -8.05 | 2509 | 6201 |
| Sitges | city | Cataluna | Spain | 41.24 | 1.81 | 0 | 26654 |
| 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 |
| Siurana | city | Cataluna | Spain | 41.26 | 0.93 | 2509 | 1136 |
| Siurana de Prades | city | Cataluna | Spain | 41.26 | 0.93 | 2509 | 1136 |
| Siviglia | city | Andalucia | Spain | 37.38 | -5.97 | 32 | 428664 |
| Sivilja | city | Andalucia | Spain | 37.38 | -5.97 | 32 | 428664 |
| Sixto | city | Galicia | Spain | 43.54 | -7.69 | 1722 | 777 |
| Sixto | city | Galicia | Spain | 43.04 | -9.01 | 1066 | 3692 |
| Sixto | city | Galicia | Spain | 42.66 | -7.07 | 3349 | 1162 |
| Sixto | city | Galicia | Spain | 43.14 | -8.87 | 830 | 3729 |
| Siétamo | city | Aragon | Spain | 42.12 | -0.28 | 1669 | 740 |
| Siñeriz | city | Asturias | Spain | 43.45 | -6.64 | 1669 | 3009 |
| Siós | city | Galicia | Spain | 42.50 | -7.60 | 902 | 4307 |