metro - Linea B Circo Massimo
The church was first built in the 8th century by Pope Hadrian I and stands on the ruins of a temple to Hercules still visible in the crypt.
Inside the church, which has been partly restored to its 8th century appearance, are remains of 11th century and medieval frescoes and a fragment of mosaics from the original St Peter's Basilica.
On the left side of the portico is The Mouth of Truth (Bocca della Verita) made of marble, that is thought to have been once an ancient drain cover.
It is said if you place your right hand into the mouth and tell a lie your hand will be bitten off, a great legend that I’m sure every-one with a clear conscience will try.