Street Art, part of the Hip-Hop culture, appeared on the walls of Reunion Island about twenty years ago. So when and by what means did reunionese people discover Street Art ? Why and how did they decide to get into this movement, becoming street artists themselves ? How did those reunionese artists made this mode of expression their own ? Finally, is there a typical reunionese Street Art ? Those are questions that this documentary will explore. “Walls can speak” is a documentary telling this story.