About 25 years ago, I saw this photo of Kurt Wenner's astonishing 'Dies Irae' and that's when I learned about madonnari. Wenner is a master of anamorphosis and trompe l'oeil, and arguably the greatest living madonnaro who reinvented the street art.
YouTube videos of some of Wenner's artworks.
It's nice that 'Masterpieces in Chalk' featuring Wenner, a National Geographic documentary made in the 1980's, is available online.
Check out Kurt Wenner's website for more information.