The gorgons in Greek mythology were three female monsters with snakes for hair. Their faces were so ugly that any man that saw their face would turn to stone. The gorgons Stheno and Euryale were immortal but Medusa was mortal. Medusa was finally killed by the hero Perseus.

Their parents were the sea god Phorcys and Ceto and they lived in the western ocean. The head of the Gorgon was often used in art. People would have a gorgon face as a door knocker to protect the house from evil. Gorgon faces were also painted inside cups.

Check that you understand what these words mean in this document
ca (abbreviation for the Latin word circa): approximately.
Immortal: never dying.
Mortal: an ordinary person who is destined to die one day.
Reverse: the back side (of a coin).