Eugene Tsui originally conceived the idea of the Ultima Tower as part of a study of the compact urban area of San Francisco. The project combines nature with urban environment on a mega scale. The tower is two miles high with a base of 6000 feet in diameter. The structure's shape is modeled after the tallest structure not made by man-- African termite nests. The Ultima Tower is 500 stories tall and is intended to house one million residents.
The tower explores the idea of stacking nature vertically to conserve space. The structure contains stacked levels of soil that form individual landscapes with "skies" between 30 and 50 meters high. Neighborhoods of architectural structures can be built on these landscapes, forming a vertical city.
The structure is designed to be energy efficient. It has built in solar panels on its exterior, self-shading glass, windmills, and a water-based cooling system. The structure also utilizes Atmospheric Energy Conversion, converts the difference in atmospheric pressure at the top and bottom of the structure into electrical power.
The base of the Ultima Tower as seen covering San Francisco: