The Foundation of Henri Cartier Bresson.
This tiny museum of Henri Cartier Bresson is a real gem for photography lovers in general and for Henri Cartier Bresson's fans in particular. The foundation is located in Montparnasse (it's not in a central place) and was founded by Cartier's daughter in order to preserve the legacy of her talented father.
Free and open late on Wednesday evenings (6:30pm to 8:30pm) and for the Friends of the Foundation. Open Tuesday—Sunday. Closed on Mondays.