the so called teshima art museum on teshima island, japan.designed by ryue nishizawa and artist rei naito, it is actually not a real art museum,although it even has a café and museum shop.
it looks quite spectacular, and being inside must be quite an interesting experience.it's made of concrete that spans up to 60 meters without support.
read more about it and see more pics here at domusweb.
click images, they are much bigger.