Mouth of Truth
A bearded face carved into a giant marble disc, the so-called Bocca della Verità or Mouth of Truth, is one of Rome's most popular curiosities. Legend has it that if you put your hand in the mouth and tell a lie, the Bocca will slam shut and bite your hand off. The mouth, which was originally part of a fountain, now lives in the portico of the Chiesa di Santa Maria in Cosmedin, a handsome medieval church.
Originally built in the VIII century, the church was given a major revamp in the XII century, when the seven-storey bell tower and portico were added and an inlaid Cosmati floor was laid. You can choose whether to visit the church only, or whether to wait in line to see the Mouth.