The big idea behind the architecture is the passage. In French, the word means a covered walkway or arcade that anyone can wander through freely. Osaka's design competition asked for exactly that at the heart of the museum: a lively indoor space open to people of all ages, not only ticket holders. Architects from around the world submitted proposals. The result is a building with no front. There are several entrances, so people can drift in from any direction, like a continuation of the street. The passage itself is a vast open atrium, 30.9 meters high, running from the first floor up through the ceiling of the fifth. Anyone can step into it, whether or not they are visiting an exhibition. Now look at that dark box again. The third, fourth and fifth floors form a single structure, and it appears to float because it rests on slender columns below, with no heavy, obvious pillars. On the second level there is a lawn plaza of about 1,000 square meters and a pedestrian deck. It links the museum to the neighboring National Museum of Art, Osaka, and to other points around Nakanoshima.