Le Musée d'Orsay: It was built between 1977 and 1981 by Piano and Rogers. Its architecture is the aim of rationalism: the structure is entirely visible and the decoration is directly made on this structure. For instance, one can see every pipe and know what it contains from its color. The iron structure is outside so as the escalators. This gives a large 5 stories place with no walls inside. This is very convenient to organize the museum around the pieces or for the temporary exhibitions. This is the French National Modern Art Museum. Collections of the XXth century, with master pieces from Picasso, Braque, Matisse, Dali, Chagall, Miro...