| Sintra to Silver Firs (Washington) | 5,167.49 mi (8,316.28 km) |
| Sintra to Silver Spring (Maryland) | 3,546.59 mi (5,707.69 km) |
| Sintra to Silver Springs Shores (Florida) | 4,108.17 mi (6,611.45 km) |
| Sintra to Silverdale (Washington) | 5,195.00 mi (8,360.55 km) |
| Sintra to Silverton (Oregon) | 5,322.80 mi (8,566.21 km) |
| Sintra to Simi Valley (California) | 5,665.24 mi (9,117.32 km) |
| Sintra to Simpsonville (South Carolina) | 3,933.61 mi (6,330.53 km) |
| Sintra to Sioux City (Iowa) | 4,355.75 mi (7,009.91 km) |
| Sintra to Sioux Falls (South Dakota) | 4,335.83 mi (6,977.84 km) |
| Sintra to Skokie (Illinois) | 3,976.92 mi (6,400.24 km) |
| Sintra to Sleepy Hollow (New York) | 3,339.16 mi (5,373.86 km) |
| Sintra to Slidell (Louisiana) | 4,466.13 mi (7,187.53 km) |
| Sintra to Smithfield (North Carolina) | 3,711.74 mi (5,973.46 km) |
| Sintra to Smithfield (Utah) | 5,041.79 mi (8,113.97 km) |
| Sintra to Smithville (Missouri) | 4,378.60 mi (7,046.68 km) |
