Welcome to The National Museum of Art, Osaka, known in Japanese as Kokuritsu Kokusai Bijutsukan. You are on Nakanoshima, the long, narrow island in the river in the heart of Osaka's Kita ward. The museum's address here is Nakanoshima, chapter four, number two, number 55, which is where the number in your listing comes from. This is a national museum with a clear focus: contemporary art made since the Second World War, from Japan and from around the world. It holds about 8,300 works, and it also stages special exhibitions that go beyond contemporary art. Here is the twist to keep in mind as you look around. Much of this museum is hidden. It was built as a fully underground museum, so what you see at street level is only the beginning. Over the next few stops, we will follow the story from a pavilion built for a world's fair, to a bamboo-inspired sculpture of steel, to the quiet galleries beneath your feet.