The Mark Center Building in Alexandria, Virginia, is the new location for the Washington Headquarters Services (WHS) of the United States Department of Defense and a number of other DoD agencies. The name of the site refers to the "Mark Center" commercial property in which it is located, at the intersection of Seminary Road and Beauregard Street at the Interstate 395 interchange.
Sixteen acres of the site were sold to the federal government and are administratively considered part of Fort Belvoir. It is the tallest building constructed by the Army Corps of Engineers.