Arlington County, Virginia area. The county is situated in Northern Virginia on the southwestern bank of the Potomac River directly across from Washington, D.C., of which it was once a part. With a land area of , Arlington is the geographically smallest self-governing county in the U.S., and by reason of state law regarding population density, has no incorporated towns within its borders. Due to the county's proximity to downtown Washington, D.C., Arlington is home to many important installations for the capital region and U.S. government, including the Pentagon, Reagan National Airport, and Arlington National Cemetery. Many schools and universities have campuses in
Rappahannock County, Virginia Rappahannock County, Virginia Rappahannock County is a county located in the Commonwealth of Virginia, US. As of the 2010 census, the population was 7,373. Its county seat is Washington. The name "Rappahannock" comes from the Algonquian word "lappihanne" (also noted as "toppehannock"), meaning "river of quick, rising water" or "where the tide ebbs and flows." Rappahannock County is included in the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area. Rappahannock County was founded by an act of the Virginia General Assembly in 1833, based on the growing population's need to have better access to a county seat. The county's land was carved from