“You can't work in the library without going into the Old Levels," said Mirelle somberly. "At least some of the time. I wouldn't be keen on going to some parts of the Library, myself."
Lirael listened, wondering what they were talking about. The Great Library of the Clayr was enormous, but she had never heard of the Old Levels.
She knew the general layout well. The Library was shaped like a nautilus shell, a continuous tunnel that wound down into the mountain in an ever-tightening spiral. This main spiral was an enormously long, twisting ramp that took you from the high reaches of the mountain down past the level of the valley floor, several thousand feet below.
Off the main spiral, there were countless other corridors, rooms, halls, and strange chambers. Many were full of the Clayr's written records, mainly documenting the prophesies and visions of many generations of seers. But they also contained books and papers from all over the Kingdom. Books of magic and mystery, knowledge both ancient and new. Scrolls, maps, spells, recipes, inventories, stories, true tales, and Charter knew what else.
In addition to all these written works, the Great Library also housed other things. There were old armories within it, containing weapons and armor that had not been used for centuries but still stayed bright and new. There were rooms full of odd paraphernalia that no one now knew how to use. There were chambers where dressmakers' dummies stood fully clothed, displaying the fashions of bygone Clayr or the wildly different costumes of the barbaric North. There were greenhouses tended by sendings, with Charter marks for light as bright as the sun. There were rooms of total darkness, swallowing up the light and anyone foolish enough to enter unprepared.
Lirael had seen some of the Library, on carefully escorted excursions with the rest of her year gathering. She had always hankered to enter the doors they passed, to step across the red rope barriers that marked corridors or tunnels where only authorized librarians might pass.”
―
Garth Nix,
Lirael
