Located in Arlington County, Virginia, it is the headquarters of the United States Department of Defense.The building has about 6,500,000 sq. ft (0.60 sq. km) of floor space, of which 3,700,000 sq. ft (0.34 sq. km) are used as offices.Designed by architect George Bergstrom and built by contractor John McShain, it was constructed 79 years ago in 1941. Officially Incredible!!
To Break The Record, An office building must measure more in floor area than The Pentagon.