The sanctuary of Eleusina (Elefsina) is located on the coast, few kilometer westward from Athens to which it was connected by the Sacred way.
The myth of Eleusina
The Demeter goddess would have offered to Triptoleme - son of the Eleusina King Keleos, the first grain of corn to thank Keleos to have accommodated his daughter Persephone who was first removed by Hades in Sicily.
Demeter would have learned to Triptoleme how to cultivate corn and would have transmitted to the Eumolpos priest the ritual of the worship of Fruitfulness. These ritual was practiced until to the IVth AC.
Photos of Eleusina