“I see,” she said at last, thoughtfully. “I see now. This garden is like the stable. It is far bigger inside than it was outside.”
“Of course, Daughter of Eve,” said the Faun. “The further up and the further in you go, the bigger everything gets. The inside is larger than the outside.”
Lucy looked hard at the garden and saw that it was not really a garden but a whole world, with its own rivers and woods and sea and mountains. But they were not strange: she knew them all.
“I see,” she said. “This is still Narnia, and more real and more beautiful then the Narnia down below, just as it was more real and more beautiful than the Narnia outside the stable door! I see… world within world, Narnia within Narnia…”
“Yes,” said Mr Tumnus, “like an onion: except that as you go in and in, each circle is larger than the last.”
~ C.S. Lewis, The Last Battle