The Last Supper

Leonardo da Vinci painted The Last Supper directly onto the refectory wall of Santa Maria delle Grazie in Milan between 1495-1498, using a tempera-and-oil technique that began deteriorating within 20 years. Despite centuries of damage, restoration, and wartime near-destruction, it attracts 1,500 ticketed visitors per day and was declared a UNESCO World Heritage Site in 1980.