The Musée d'Art Moderne de la Ville de Paris takes up part of the Japan Pavillion. The museum part is very spare. It looks like this other part of the building, closed off, was more interesting,to the point of being garish. It looks like it might have held some kind of art exhibits at some point--you can see a hint of some murals up at the top of the pictured stairs. It seemed like more ofan art-mural than a pavillion-mural, if that makes any sense.