Upon Demeter's wandering she traveled to the city of Eleusis, and the palace of King Celeus. The King's wife, Metaneria, welcomed Demeter into her home and hired her to look after her new son, Demophon. Demeter took excellent care of the infant by nourishing him on ambrosia, and at night placing him in the fire to burn away all that was mortal of him. One day Metaneria discovered the child in the fire and was horrified. Demeter revealed herself and demanded a temple be built there.
Demeter is also known for founding the Eleusinian Mysteries. These were huge festivels held every five years. They were importaint events for many centuries. Yet, little is known of them as those attending were sworn to secrecy. The central tenant seems to have been that just as grain returns every spring after its harvest and wintery death, so too the human soul could be reborn after the death of the body.
Hades, god of the underworld, abducted [Demeter's] daughter Persephone. Demeter asked Zeus, a brother of Hades, to return Persephone. When Zeus refused, Demeter withheld the harvest from man until Zeus relented. He agreed to allow Persephone’s return if she had not eaten while with Hades. However, since Persephone had eaten 6 pomegranate seeds in the underworld, Zeus determined that she would spend 6 months with her mother and 6 months with Hades. This is the mythic origin of the six months of spring and summer when Persephone walks the earth with her mother and the 6 months of fall and winter when Persephone must return to the underworld.