Virginia State Route 120 is 9.10 miles long with nine separate locations, one of which is Arna Valley (towns may be incorporated within counties).
Under Virginia law, towns may be incorporated within counties; however, the state does not permit the creation of any new incorporated towns within a county that has a population density greater than 1,000 persons per square mile. The entire route is in Arlington County. Crystal City mi 0.00 Arna Valley Westmont Arlington Heights Ballston Glebewood Donaldson Run Rivercrest Arlingwood 9.10 
