21st Century Museum of Contemporary Art

Designed by the acclaimed Tokyo architecture firm SANAA, this ultramodern museum opened in late 2004 and instantly became an 'it' building. A low-slung glass cylinder, 113m in diameter, forms the perimeter, and inside galleries and auditoria are arranged like boxes on a tray. Nongallery portions of the building are open daily from 9am to 10pm.

Oh yes, there's art too: temporary exhibits by leading contemporary artists from Japan and abroad, plus occasional music and dance performances. Check the website for events; admission charges may increase up to ¥1000 during special exhibitions.