Tokyo Bay millennium tower, c 1996.

Architectural model. At 840m tall, the Millenium Tower in Tokyo would have been twice the height of the Chicago Sears Tower. It was designed to hold 50,000 people and support a mixture of work and leisure activities. 'Town squares' every 30 floors would have divided the tower into localities similar to neighbourhoods, and high-speed lifts the size of buses would have carried up to 150 people through its helical steel structure. The tower was never built; it became a victim of the bursting of the real estate bubble in Japan in the late 1990s.