Lethaea is a mythological character briefly mentioned in Ovid

Ovid

Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria...

's Metamorphoses. Due to her vanity, she was turned to stone at Ida

Mount Ida, Crete

Mount Ida, known variously as Idha, Ídhi, Idi, Ita and now Psiloritis , is the highest mountain on Crete. Located in the Rethymno Prefecture, it is sacred to the Greek Titaness Rhea, and on its slopes, according to legend, lies the cave, Idaion Andron, in which Zeus was born...

 by the gods. Her lover Olenus

Olenus

In Greek mythology, Olenus was the name of several individuals:#Olenus, son of Hephaestus and father of Helice and Aex, two nurses of infant Zeus. A city in Aulis was named for him....

 wished to share in the blame, and so shared her fate. The story is used as a metaphor for how stunned Orpheus

Orpheus

Orpheus was a legendary musician, poet, and prophet in ancient Greek religion and myth. The major stories about him are centered on his ability to charm all living things and even stones with his music; his attempt to retrieve his wife from the underworld; and his death at the hands of those who...

was after a failed attempt to bring back his wife from the underworld. It was as if he too were turned to stone.