The Sanctuary of Demeter lies on an eastern slope, at the foot of the ancient acropolis protecting the settlement of Eleusis, hardly visible amid the modern buildings of the main square of Elefsina (or Eleusis, as it was called in the ancient Greek world). The legend of Demeter and her daughter Persephone explained for the ancients the cause of the seasons and the origins of agriculture.
It was to Eleusis that Demeter traveled in search of Persephone after the girl
had been kidnapped by Hades, god of the underworld. Zeus himself interceded to restore her to the distraught Demeter but succeeded only partially, giving mother and daughter just half a year together.
Nevertheless, in gratitude to King Keleos of Eleusis, who had given her refuge in her time of need, Demeter presented his son Triptolemos with wheat seeds, the knowledge of agriculture, and a winged chariot so he could spread them to mankind. Keleos built a megaron (large hall) in Demeter's honor, the first Eleusinian sanctuary.
The worship of Demeter took the form of mysterious rites, part purification and part drama, and both the Lesser and the Greater Eleusinian rituals closely linked Athens with the sanctuary. The procession for the Greater Eleusinia began and ended there, following the route of the Sacred Way (along the avenue still called Iera Odos today).
Much of what you see now in the sanctuary is of Roman construction or repair, although physical remains on the site date back to the Mycenaean period. Follow the old Sacred Way to the great propylaea (gates) and continue on to the Precinct of Demeter, which was strictly off-limits on pain of death to any but the initiated. The Telesterion (Temple of Demeter), now a vast open space surrounded by battered tiers of seats, dates to 600 BC, when it was the hall of initiation. It had a roof supported by six rows of seven columns, presumably so the mysteries would be obscured, and it could accommodate 3,000 people.
The museum, just beyond, contains pottery and sculpture, particularly of the Roman period. Although the site is closed at night, you can see the sacred court and propylaea from a distance thanks to special lighting by Pierre Bideau, the French expert who also designed the lighting for the Acropolis in Athens.