The Bocca della Vertia (or the Mouth of Truth) is believed to have been built before the 4th Century BC and designed as a drain cover. There is a legend that says it was designed as a lie detector and that the powerful jaws will descend on the hand of anyone who tells a lie. The Bocca della Vertia may be a grim looking piece of ancient Roman statuary, but it also carries a sheen of romance since being featured prominently in one of the most romantic movies ever made, ‘Roman Holiday’, with Audrey Hepburn and Gregory Peck.