Book Nook in a fireplace that is no longer usable. Very creative use of space. Just make sure to clean that fireplace well before putting any books in there and to seal things to prevent water damage or pests from coming down the chimney.
Great idea to maximize space in a basement.hallway library going not quite down the center of basement with small sleeping nook off of bookcase side and doorway to another room, maybe a play room/movie room
Awesome bookmarks help you take notes without writing in your books. I always want to remember quotes or important lessons each book offers. I also have hard time keeping characters straight if it's a complicated story.