On May1, Google honoring the 160th Anniversary of the World's First Fair with a special doodle. The World's Fair took place in The Crystal Palace in Hyde Park, London, United Kingdom in 1851.
The event was invented by the Prince Albert, Queen Victoria's husband to celebrate modern industrialism and was hosted at the Crystal Palace, a massive glass exhibition centre designed specifically for the event.
This Google logo is interactive, a growing change in how Google makes their logos. The logo lets you use your mouse pointer as a magnifying glass to see the picture in more details. A full size version of the logo can be seen over here.
Here're the picture(s) how the doodle looks when you place your mouse over sections of it:
Here's the YouTube video in action: