Suitland Federal Center, Maryland

Suitland Federal Center is a secure federal site with a number of information gathering, storage, processing, and management facilities. On site is the headquarters of the US  Census Bureau, the National Maritime Intelligence Center, National Archives Washington National Records Center, a Federal Protective Services mega center, and a NOAA satellite operations facility that is mostly underground. The site has been used by the federal government since 1941, and several agencies have had facilities here, including the Naval intelligence and photographic interpretation operations. Underground vaults were constructed as early as the 1946, intended to store important documents, including the Constitution and the Declaration of Independence, as well as microfilm and other media, an even, they say, artworks and artifacts from the Smithsonian, in the event of an attack on Washington. While some of these facilities may still exist, here or elsewhere, the last of the primary vaults, A, B, and C, were said to be demolished after a fire in the mid 1990s.