| Alton to Sesimbra | 962.61 mi (1,549.17 km) |
| Alton to Setubal | 953.33 mi (1,534.24 km) |
| Alton to Sever do Vouga | 801.56 mi (1,289.98 km) |
| Alton to Silves | 1,031.89 mi (1,660.67 km) |
| Alton to Sines | 989.58 mi (1,592.58 km) |
| Alton to Sintra | 945.75 mi (1,522.05 km) |
| Alton to Sobrado de Paiva | 780.49 mi (1,256.07 km) |
| Alton to Sobral de Monte Agraco | 926.90 mi (1,491.71 km) |
| Alton to Soure | 850.46 mi (1,368.69 km) |
| Alton to Tabua | 818.43 mi (1,317.14 km) |
| Alton to Tavira | 1,023.45 mi (1,647.09 km) |
| Alton to Tomar | 874.82 mi (1,407.89 km) |
| Alton to Tondela | 809.51 mi (1,302.78 km) |
| Alton to Torre de Moncorvo | 747.26 mi (1,202.59 km) |
| Alton to Torres Novas | 885.68 mi (1,425.37 km) |
