The Wood Between the Worlds

The wood between the worlds is a place where you can find your way to any other Oxford College. You go down into the pool and re-emerge in Narnia or Charne as it may be. There seems to be the suggestion that there's an infinite number of worlds that the wood and its pools give you access to. But I'm not entirely clear about that. Aslan made it because Aslan is the divine ruler of this whole sub-created imagined world that C.S. Lewis is giving us.