All of you must have aware of the Google Doodles, the special Google logo on the famous historic Events. Today is May 1st and Google had displayed a very nice and interactive Logo for the 160th Anniversary of the First World's fair. As you mouse over the logo a magnifying glass will apear and it will show you many hiden items there in clear focus. The display has Google name with various events and shows.
See video for it
The First world's Fair was held in the Crystal Palace in Hyde Park, London, United Kingdom in 1851 under the title "Great Exhibition of the Works of Industry of All Nations". The Fair was opened by Queen Victoria.
Since then there are many such fair were organized. Know more about World Fair on Wikipedia.
Also want to see more Google Doodles go to the link (Google Doodles link).