'it's an awfully big wardrobe...'

It was certainly an awesome place, a round green hill on top of another hill, long since grown over with trees, and one little, low doorway leading into it. The tunnels inside were a perfect maze till you got to know them, and they were lined and roofed with smooth stones, and on the stones, peering in the twilight, Caspian saw strange characters and snaky patterns, and pictures in which the form of a Lion was repeated again and again. -from C. S. Lewis's "Prince Caspian" and here