Cave of Mayrières Supérieure

A prehistoric cave near Bruniquel in Tarn-et-Garonne, France, that once contained two 15,000-year-old bison paintings -- the only decorated cave in the department. In 1992, approximately 70 members of the Eclaireurs de France scouting association entered the cave with steel brushes to remove modern graffiti, inadvertently destroying the irreplaceable prehistoric artwork in the process. The incident earned them the 1992 Ig Nobel Prize in Archaeology. The cave was officially classified as a historical monument in 1993.