Every Night the U.S. Constitution, the Bill of Rights, and the Declaration of Independence Are Lowered Into A Bomb-Proof Vault
Where do they keep the Charters of Freedom, which is the collective name for the U.S. Constitution, the Bill of Rights, and the Declaration of Independence, when these aren't on display at the National Archives building?
Answer: Underground in a bomb-proof vault.
According to Atlas Obscura, "Every night (and at the press of a button, should the need arise) a special elevator pulls them underground into a custom-built armored vault.
The original vault was built in 1953 by the Mosler Safe Company. The firm was the logical choice, having previously taken on notable achievements like the gold bullion vault at Fort Knox, and a bank vault in Hiroshima that survived an atomic bomb."
You can see the swift movement of the documents being lowered into the vault in this 1953 documentary:
The original vault was "replaced in the early 2000s... the current vault, designed by Diebold, is still shrouded in secrecy." When David Ferrier, Archivist of the United States at the National Archives, was asked by NY Mag's Dan Amira about the storage of these founding documents, and a plan to keep them safe in case of, say, a nuclear blast, Ferrier answered, “We do have a plan, BUT I’d have to kill you if I told you... security arrangements for the Charters are not public.”
A 1990s TIME article, however, unveiled a doomsday plan that was put in place between 1979 and 1981—they stated that "though the National Archives building has a 55-ton steel-and-concrete vault on the premises, the scenario calls for the evacuation of these and other documents, probably by helicopter, to an underground facility, if there is adequate warning time."
You can visit the original Declaration of Independence, Constitution of the United States and Bill of Rights in The Rotunda for the Charters of Freedom, located on the upper level of the National Archives museum, from 10 a.m. to 5:30 p.m.