Cascades is a census-designated place (CDP) in Loudoun County, Virginia, United States. The population as of the 2010 United States Census was 11,912. Along with nearby Countryside and Lowes Island, it is considered one of the three main components of the Potomac Falls community (ZIP code 20165) within Sterling, Virginia. * The entrance to the Cascades community along Cascades Parkway at Palisade Parkway. The Cascades logo can be seen in the lower right. * Leaving Cascades along Cascades Parkway toward Virginia State Route 7 * The main office of the Cascades homeowners association * * * * * * *