Today is the 160th Anniversary of the First World’s Fair, which was organized in The Crystal Palace in Hyde Park, London, United Kingdom in 1851. The first fair, styled as the “Great Exhibition of the Works of Industry of All Nations”, was basically the idea of Prince Albert, Queen Victoria’s husband. About 300 such fairs have been held since.
To commemorate the historic event, Google home page features an exclusive interactive logo. Here is how the logo appears when you mouse over specific sections of it: