Cripta

The Basilica of Saint Mary of Cosmedin — the portico of which is home to the Bocca della Verità — was built on the ancient Forum Boarium.
Beneath the church lies “Hadrian’s crypt”.  (Not the emperor.  The name of the pope that built the church, usually rendered as Adrian I.) The name “Cosmodin” comes from a Greek word meaning “decoration” (and, etymologically, is related to the word for “order” which is why the words “cosmology” and “cosmetology” look so similar even though they have such radically different meanings.)