La Bocca della Verità (the Mouth of Truth) Santa Maria in Cosmedin.
The Basilica was built in the 8th century over an ancient temple dedicated to Hercules.
Before entering the church, pass the road opposite to the piazza to admire Tempio di Ercole Vincitore. The Temple of Hercules Victor is an ancient edifice almost 11 meters tall. Back in the second century BC, it used to be a round temple. It is the city’s earliest surviving marble building.