Annandale is a census-designated place (CDP) in Fairfax County, Virginia. The population of the CDP was 41,008 as of the 2010 United States Census.EtymologyAnnandale derives its name from Annandale in Scotland.GeographyAnnandale is located at . Annandale is mostly traversed by the Capital Beltway and Virginia State Route 236. The center of town is considered to be where Route 236, Columbia Pike, and Backlick Road meet around two miles east of Interstate 495 on Route 236.According to the United States Census Bureau, the CDP has a total area of 7.86sqmi, all of it land. The area is part of the coastal plain located just east of the Fall Line separating the coastal plain of Virginia from the piedmont. It is characterized by rolling hills, stream valleys, and heavy red clay soils.The Annandale region is bisected by Accotink Creek, which in Colonial times was a primary link for ocean-going ships that would load tobacco and other goods where Little River Turnpike - Annandale's oldest road and the first toll road in America - crosses it. With the construction of the Springfield Dam in 1918, Lake Accotink was created to serve as a water source for World War I Army Camp A.A. Humphreys. In 1960, when the lake was no longer needed by the Army, the Fairfax County Park Authority leased the land and finally bought the site in 1965. Today, Lake Accotink is a popular recreation area with bike trails, fishing and boat rentals.