La Bocca della Verità

La Bocca della Verità (the Mouth of Truth) is a very famous sculpted image of a human face, in Rome, and it is thought to be part of an ancient Roman fountain portraying a river god. But that is not the reason for its popularity, the reason is its capability of acting as a lie detector, which dates since the Middle Ages. It was believed that if a person told a lie with his hand in the mouth of the sculpture, it would be bitten off.