This most famous, and probably most beloved of the Narnian tales was the first one written, and probably the best place to start. I have heard that the author wished for children to read this book first and then go back to The Magician's Nephew afterward.

Four British children - Peter, Susan, Edmund, and Lucy, are taken to the country to live with an old Professor during World War II, as London was quite unsafe for children. The professor is somewhat eccentric, but kind, and permits them to explore his large estate. While hiding in an old wardrobe, the youngest, Lucy, is amazed to discover that there is no back to the wardrobe - as she pushes past more and more coats, they become scratchier and colder and she begins to realize that she's no longer in a wardrobe. She's in the middle of a snowy forest. Lucy has discovered a strange, unknown world where amazing adventures await her and her siblings.

Long beloved by children the world over, this is a tale of innocence, difficult lessons learned, adventure, friendship and love. Underneath and not immediately apparent to children is an allegory. Some truths about our own world can be seen more clearly through a story that takes place elsewhere.

Narnia is in the grip of the White Witch. Although she promises happiness and delightful things, those who follow her are miserable, and the entire land is immersed in an eternal winter - always winter and without Christmas. The mysterious Aslan, a lion who is greatly feared by the witch, comes to Narnia and things begin to change.

Most parents will quickly realize that Aslan is a figure for Christ who saved the world from the tyranny of sin and death (represented by the witch). There are many interesting details that correspond with this allegory. Although I read the series many times as a child, I wasn't fully aware of the allegorical significance until much later. I wouldn't spoil it for children by sitting down and explaining it to them. The Christian allegory will probably be more meaningful if they are permitted to discover it for themselves.

The story (as well as others in the series) is appropriate as a read-aloud even for rather young children and is written at a mid-grade-school reading level. (Strong readers may be interested in tackling it even earlier.) The book is most powerful, I think, when it can be first introduced in the very simple way that young children enjoy such a book.