Demeter. Persephone. Hades. Three names well-known from Greek mythology. Like Perseus slaying Medusa, or Theseus with his ball of thread, the story of Persephone's descent to the Underworld* is one known even outside Pagan communities. The details might be lost, but most people can recite the broad outlines of the tale: Hades kidnaps Persephone and takes her down to the Underworld and her mother, Demeter, is so upset that she withholds her blessings from the Earth. Winter sets in. Only when her daughter is returned does Demeter allow the crops to grow again.
Like I said: broad outline. There are many, many different ways to interpret this myth -- coming-of-age tale, the reason for the seasons, origins of a mystery tradition, incorporation of a foreign Deity into the indigenous pantheon, and so forth. There are also different versions of this myth -- ancient, modern, feminist, and even (re)written Christian morality plays.
The story often appears in children's collections of Greek and Roman mythology. One of the oldest which has been continually reprinted is Nathaniel Hawthorne's Tanglewood Tales. Originally published in 1853, Hawthorne (who uses the Latin Deity names) explicitly notes in his introduction that he sought to render the old myths "presentable to children." He continues: "These old legends, so brimming over with everything that is most abhorrent to our Christianized moral sense. [....] was such material the stuff that children's playthings should be made of! How were they to be purified? How was the blessed sunshine to be thrown into them?"