One of the three rooms for Marcel Duchamp's works. This is the the largest collection worldwide of Duchamp. One of us did not understand that you need to peep through tiny holes to get to the famous pornographic piece: "Étant donnés: 1. La chute d’eau, 2. Le gaz d’éclairage ..."
( you may want to check it at http://leftbankartblog.blogspot.com/2009/12/marcel-duchamps-etant-donnes-at.html ).