The Last Supper, or Cenacolo,  by Leonardo da Vinci is a mural painting on the north wall of the dining hall in the Dominican Convent Santa Maria delle Grazie. The convent construction began by the half of 1400 and it miracolously escaped the bombings of 1943.The  Cenacolo was created by Leonardo da Vinci for his patron Lodovico Sforza, Duke of Milan, as it is witnessed by a letter dated 19th June 1947. It  represents the scene of Jesus Christ’s Last Supper as the Bible describes it. The painting is based on the narration in the Gospel of John (13:21), when Jesus announces that one of his disciples would betray him.Leonardo choose to portray the climax moment of the supper, the reaction given by the apostles when Jesus says that someone of them would betray him, causing shock and wonder: the disciples begin to move, those who have not heard Jesus’ words stand up, some of them get frightened, like Jude as he feels his plan has been revealed.Leonardo choose the “secco” (on dry wall) technique rather than of the fresco technique (on wet plaster) which was traditionally used for mural paintings.A major restoration project began in 1977: the restoration took  21 years and it involved scientists, researchers, critics and many restorers. The painting has been declared universal property by the UNESCO.Groups of a maximum of 25 visitors are admitted for a 15 minutes show. This rule wants to preserve the special ambient conditions (controlled by means of a special air treatment), necessary for the conservation of the painting.