Libraries hold more than books. They even contain more than the extended list of magazines, music CD’s, and movies which many people would tack on behind books. (Or maybe in front.)
People — employees and patrons — also populate the library building. Numbers depend on the size of the library.
And some libraries hold surprises. The day I visited the library in a mid-size Wisconsin city — I was donating books — I went to the upstairs level and browsed in an art show.