Before the Cambridge Public library was renovated it had a multistory section that housed the stacks. After the renovation part of this space been repurposed as the Young Adult section. When I first started using the library in the 60s it was a closed stack; you'd look up stuff in the card catalogue and then fill out a request slip and someone would get your books. Later they made it open which was much more useful because you could browse, but some people did not like the potentially treacherous stairs and floors (especially not good for high heels).
It had a really neat system of flooring and shelving.