The Art Institute of Chicago's API includes a field called 'has_not_been_viewed_much' that indicates if an artwork has been viewed fewer than 200 times on their website since January 1, 2010. This field can be used to discover lesser-known artworks. The API provides access to a large collection of artworks, and users can browse through them. The 'has_not_been_viewed_much' field is a boolean value that helps users find hidden gems in the collection.