A deeper country

'The Eagle is right,' said the Lord Digory. 'Listen, Peter. When Aslan said you could never go back to Narnia, he meant the Narnia you were thinking of. But that was not the real Narnia. That had a beginning and an end. It was only a shadow or a copy of the real Narnia which has always been here and always will be here: just as our own world, England and all, is only a shadow or copy of something in Aslan's real world. You need not mourn over Narnia, Lucy. All of the old Narnia that mattered, all the dear creatures, have been drawn into the real Narnia through the Door. And of course it is different; as different as a real thing is from a shadow or as waking life is from a dream.'

It is as hard to explain how this sunlit land was different from the old Narnia as it would be to tell you how the fruits of that country taste. Perhaps you will get some idea of it if you think like this. You may have been in a room in which there was a window that looked out on a lovely bay of the sea or a green valley that wound away among mountains. And in the wall of that room opposite to the window there may have been a looking-glass. And as you turned away from the window you suddenly caught sight of that sea or that valley, all over again, in the looking-glass. And the sea in the mirror, or the valley in the mirror, were in one sense just the same as the real ones: yet at the same time they were somehow different—deeper, more wonderful, more like places in a story: in a story you have never heard but very much want to know. The difference between the old Narnia and the new Narnia was like that. The new one was a deeper country: every rock and flower and blade of grass looked as if it meant more. I can't describe it any better than that: if ever you get there you will know what I mean.
(C.S. Lewis, The Last Battle)