Arlington County is a county in the Commonwealth of Virginia. It is also considered by the Census Bureau to be a Census-designated place, and the second-largest Principle City of the Washington metropolitan area. It is known in the region simply as Arlington or Arlington, Virginia. In 2013, the population was estimated to be 227,146, and would be the fourth-largest city in the state if it were incorporated as such.
source:wikipedia\Image by: Arlington County