It's purely theoretical for now, but it's nice to dream. The X-Seed 4000 is a 13,123 ft (4 kilometre) tall skyscraper with a 6 square kilometre footprint, with room for half a million to a million residents. It's based on Mt Fuji, and designed for Tokyo by the Taisei Corporation, the same company who built Japan's first subway in 1927, and who are currently tunneling under the Bosphorus to link the European and Asian sides of Istanbul.

[via Inhabitat]

Technorati Tags: architecture, design