La Bocca della Verità ("The Mouth of Truth") is located in the Basilica di Santa Maria in Cosmedin, very near the Isola Tiberina. The large stone circular image of a bearded, horned man (possibly a river god or Oceanus, god of the sea) likely served as a drain cover during ancient Roman times. Today, however, it is not visited for its association with water. The figure has long been considered to be a means to test honesty. As Gregory Peck informs Audrey Hepburn in "Roman Holiday," legend states that if you place your hand in the figure's mouth and tell a lie, the giant stone slot of a mouth will smash down and bite your hand off. Centuries ago, this crude form of a lie-detector test was often used to test the fidelity of wives. Today, the Mouth of Truth is a popular tourist attraction, where the violent legend is turned in to a prime photo spot.
The Mouth can be seen at any time of the day through the iron bars around the basilica's porch, and it can be visited during normal daytime hours. If you see a tour bus parked on the piazza, come back later. The line to visit the Mouth is usually fairly long, and if you want to take both the traditional smiling tourist picture and the screaming, hand-in-sleeve Gregory Peck pictures, you’ll want to visit when there are only five or six other people in line.
Getting to the Mouth of Truth is fairly easy, and the piazza houses several other interesting ancient structures. The piazza is less than a mile’s walk from Piazza Venezia, and it is impossible to miss if you walk along the river from the island. The trip is scenic and only slightly off of the usual tourist route, so it can be a nice break from the crowds. Particularly if you’re one of those people who wants to actually touch the ancient art pieces you see all over Rome, this spot is for you – not only are there no security guards telling you to keep your hands off, but you’re expected to have a hands-on experience. It’s a chance to literally reenact history, not to mention get a fun picture at the same time.