Bocca della Verità, or Mouth of Truth, is an ancient lie detector. According to superstitions, if a liar puts their hand into the mouth on the frieze, that hand will then be bitten off. The stone disc dates back to around the 1st century CE and no one is sure why it was created. Some say it is a ceremonial well cover or decoration, but others say it represents the face of a pagan god. It featured in an amusing scene in the 1953 film “Roman Holiday” with Gregory Peck and Audrey Hepburn.