Chances are you have seen library ladders in your local library or bookstore, and while the majority of us may not have such a collection of books that we would need a library ladder to access them, a ladder bookshelf makes a great item to keep books on as a display unit. It will add a sense of old world charm to your living room or den and is as functional as it is attractive.
Library ladder bookshelf:
Library ladder bookshelves pictured: Left: 5-Tier Leaning Wall Shelf Ladder Shelf in Black by eWayMarket / Right: Nexxt Hadfield 5-Tier Leaning Wall Shelf, White by Nexxt by Linea.
These tend to be used for displaying small item, or a small amount of books.