As The Passion of C.S. Lewis points out, The Chronicles of Narnia aren’t allegory — at least not by a strict definition:
C.S. Lewis, however, always claimed that The Chronicles of Narnia were not allegorical. ‘You are mistaken when you think that everything in the books ‘represents’ something in the world,’ he wrote to a group of schoolchildren. ‘Things do that in The Pilgrim’s Progress but I’m not writing that way.’