The Art Institute of Chicago's API includes a has_not_been_viewed_much field on artwork. It's a boolean that describes whether an art piece hasn't been visited on their website very much.

More specifically, per the source code , has_not_been_viewed_much means the art piece has been viewed fewer than 200 times on the website since January 1, 2010.

Of course, that still begs the question: what are these artworks? Why aren't they being viewed? I can't answer the latter, but, if you have a moment for the former, please take some time to browse.