Leonardo da Vinci’s Mona Lisa is acclaimed as "the best known, the most visited, the most written about, the most sung about, the most parodied work of art in the world." It’s probably the most iconic art work of all time, not just because of its beauty, but because of the mystery and controversy surrounding it.

The Mona Lisa was apparently one of the most revered works of Da Vinci. The artist claimed that it was his finest accomplishment, and he brought the painting with him wherever he went.

There are countless explanations and conspiracy theories behind the Mona Lisa. Some say that it is the portrait of Lisa Gherardini, the wife of Francesco del Giocondo. Others believe that it is a portrait of Leonardo da Vinci himself, and computer analysis of the painting do show several congruencies in their faces.

The smile upon the portrait’s face also drew a lot of questions and theories, but perhaps the most well-known hypothesis is the one presented in Dan Brown’s bestselling novel, The Da Vicni Code.  In the book, the main character Robert Langdon states that Leonardo da Vinci purposely painted the Mona Lisa to celebrate the balance between male and female.

While the person in the Mona Lisa looks like a woman at first glance, a closer look would indicate that the subject has androgynous features.  The Da Vinci Code suggests that the person is neither male nor female. To support this, Langdon takes breaks down the name Mona Lisa and shows that it is an anagram for “AMON”, the god of male fertility and Isis, the goddess of female fertility, whose ancient pictogram was once called “L’ISA”.

Put the two together and you get Mona Lisa. According to the book, “Not only does the face of Mona Lisa look androgynous, but her name is an anagram of the divine union of male and female. And that, my friends, is Da Vinci’s little secret, and the reason for Mona Lisa’s knowing smile.”