what county is arlington va
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 . In 2014, the county's population was estimated to be 229,302, which would make it the fourth-largest city in the Commonwealth if it were incorporated as such.