Eleusis.
At her sanctuary in Eleusis.
Olympus
the greek goddess Demeter was born on the earth, no known exact location but she was put there to help the farmers plant and yield and those sort of things
No, the Greek goddess Demeter does not have a last name, she does have titles and epithets.
ask percy jackson
You do know that she's not real, right? She can't have a "last known location" if she never existed.
Demeter's worship is known as the Eleusinian Mysteries.
She is a Greek goddess so her last location would be Ancient Greece.
hell
pooooop
The sea.
greek myths she is known as Demeter. In roman she is known as Ceres.