'Art is the queen of all sciences communicating knowledge to all the generations of the world.' There might be no better day to ponder these inspirational words by Leonardo da Vinci than World Art Day. Celebrated on April 15, this day marks the birthday of the renowned Renaissance artist. From his iconic painting of the Mona Lisa to his detailed sketches of flying machines, Leonardo's legacy pushes the boundaries of knowledge and talent in a wide range of fields. Today's homepage shows the RedBall Project at Centraal Station in Antwerp, Belgium. Created by the American artist Kurt Perschke, this travelling public art installation is considered to be 'the world's longest-running street artwork.' It showcases a 4-metres inflated red ball that has been wedged into dozens of landmarks in countries from Australia to England since 2001.