Inaugurated in 1996, the building was planned from 1989, when the dedicated international design competition was won by the famous Uruguayan architect Rafael Viñoly. The building includes one of the largest theaters in the world, conference rooms, exhibition space, restaurants and shops and is used for all kind of events, from exhibitions and conventions to concerts and even flea markets.
If you wish to visit it (which I highly recommend, at least to admire this thrilling glass hall), the Tokyo International Forum can be easily accessed with the JR trains - it is located between the Tokyo Station (Marunouchi South exit) and Yurakucho Station. Alternatively, you can go there with the Tokyo Metro (via Yurakucho Station).
EXIF info:
Nikon D90
Lens: 8-16mm F/4.5-5.6G
Focal Length: 8mm
Aperture: F/7.1
Shutter Speed: 1/320s
ISO Sensitivity: ISO 400