The first mentions of April Fool's Day date from the early 16th century, although there is no indication of origin of some of the best April 1st jokes. In 1960, there was a report in a Dutch journal that the Tower of Pisa had fallen down. In the 70s a sculptor erected a fake Easter Island statue on the beach of Zandvoort. In 1998, Burger King, announced that they would introduce a Whopper Burger for left-handed people. In 2005 a report stated that a zebra had given birth to a checkered baby at Emmen Zoo. In 2011 Rotterdam Zoo had supposedly invented a muzzle for sharks (to stop them from biting).