Arlington County is a county in the Commonwealth of Virginia. It is coterminous with the U.S. Census Bureau-census-designated place of Arlington, which is the second-largest principal city of the Washington metropolitan area. As a result, the county is often referred to in the region simply as “Arlington” or “Arlington, Virginia”.
The county is situated in Northern Virginia on the south bank of the Potomac River directly across from Washington, D.C. Arlington is also bordered by Fairfax County and City of Falls Church to the northwest, west and southwest, and the City of Alexandria to the southeast. With a land area of 26 square miles, Arlington is the geographically smallest self-governing county in the United States, and due to state law regarding population density, has no other incorporated towns within its borders.
It is the highest-income county in the United States by median family income, though it has the highest concentration of singles in the region. According to a 2016 study by Bankrate.com, Arlington is the best place to retire, with nearby Alexandria coming in at second place. Criteria of the study included cost of living, rates of violent and property crimes, walkability, health care quality, state and local tax rates, weather, local culture and well-being for senior citizens.
In October 2008, BusinessWeek ranked Arlington as the safest city in which to weather a recession, with a 49.4% share of jobs in “strong industries”. In October 2009, during the economic downturn, the unemployment in the county reached 4.2%. This was the lowest in the state, which averaged 6.6% for the same time period, and among the lowest in the nation, which averaged 9.5% for the same time.
source: wikipedia.org