The Eastman House is an International Museum of Photography housed in the former estate of George Eastman, founder of Eastman Kodak company, and founding father of photography in America. The museum has recently expanded, and the site includes a bookstore, a theater, cafe, and gardens. The mansion is filled with both permanent exhibits of photography and Eastman's contributions, the history of Kodak, etc. as well as travelling exhibitions.
Definitely worth spending a few hours here - it's surely a pilgrimage site if you're a photographer or remotely interested - just note, it's closed on Mondays.