Do Not Open: An encyclopedia of the world's best-kept secrets is a book published on October 25, 2007 by Dorling Kindersley and written by John Farndon.

The book deals with Air Force One, the U.S. President's personal jet, and the secrets behind the Turin Shroud to Nostradamus and the lost city of Atlantis. The book also has information about fake diamonds, behind the scenes of movie studios, flags, underground in Paris and strange weather.