Leonardo da Vinci's 16th Century work the Mona Lisa is probably the most recognisable piece of art in the world. Well, maybe second to maybe The Scream, The Girl With The Pearl Earring or that sticker of the kid peeing on football shirts you see in the back window of people's cars. What is it that's so beguiling about this particular portrait? What made it "the best known, the most visited, the most written about, the most sung about, the most parodied work of art in the world"? Why this painting above all others, let alone all others in the impressive and sizeable oeuvre of literal renaissance man da Vinci? Well, as much as it pains us to admit it, we think Dan Brown might have been onto something.
The Da Vinci Code might be a bit of a hacky, pulpy thriller that has made way too many people believe in ridiculous conspiracy theories, but they tap into something that's genuinely fascinating about the artist's work, and especially the Mona Lisa. There actually are a whole bunch of hidden mysteries, secret messages and ongoing rumour surrounding the portrait - five hundred years after it was painted. Critics, historians and Brown fans alike are still arguing about everything from Lisa's identity to whether it was actually a much larger picture that got cut down for some reason.
That's not even the nuttiest thing that people have read into this quincentgenarian artwork - to be honest, we reckon even Dan would have a problem getting his head around some of these. Here are eight hidden secrets in the Mona Lisa.