Louvre, Paris, FRANCE

30 years ago, a new entrance was created to get inside the Louvre museum. It is a big pyramid in the middle of the courtyard, designed by the architect Ieoh Ming Pei. To celebrate the anniversary, the artist JR did an artwork in the courtyard. 400 people covered the ground and the pyramid with paper. But it didn’t last very long. Two days later, it was a big mess and cleaners started sweeping it away.