According to Greek mythology, the Gorgons were three sisters, Medusa, Euryale and Stheno.
Gorgons were monstrous creatures, covered with impenetrable scales, with brass claws and sharp fangs. Anyone who laid eyes upon one of them them would turn to stone. They lived in the ultimate west, near the ocean, and guarded the entrance to the underworld.
According to one myth, Medusa was the only Gorgon to have hair of living snakes. She was also the only Gorgon one that was mortal.

Medusa was killed by the hero Perseus, who fought her using a mirror to avoid being turned to stone.

Even after death, Medusa's head still  has the power to turn those who gaze upon it to stone. It is said that her head it is buried somewhere in the Greek town of Argos.