Three arcology designs:
- Ziggurat: a carbon-neutral pyramid-shaped building in Dubai that would have a 2.3 sq. km footprint (at least, I assume that number is the area covered by the base) and would house 1.1 million people.
- X-Seed 4000: a sort of funnel-shaped building in Tokyo that would have a 6 sq. km footprint, would be 13,000 feet tall, and would house 500,000 to a million people.
- Ultima Tower: about 150 sq. km, 10,560 feet tall, housing a million people. Designed in 1991.
My impression is that none of these are actually intended to be built. But they're pretty cool designs.
I got a bunch of this info via a website called Inhabitat: "future-forward design for the world you inhabit." An interesting mix of architecture, sustainability and eco stuff, and fashion/lifestyle stuff.