Shimizu Mega-City Pyramid
Shimizu imagined one million people living above Tokyo Bay inside a lattice pyramid two kilometres wide and taller than any completed building.
Quick facts
- Existence state
- Never Born
- Peak stage
- documented concept
- Research confidence
- high
- Last verified
What it was
A conceptual arcology proposed by Japan's Shimizu Corporation for Tokyo Bay.
The scheme stacked neighbourhoods, transport and services inside a lightweight tubular frame whose scale depended on materials not yet practical.
Existence timeline
Shimizu presents a giant inhabited pyramid for Tokyo Bay.
The proposal divides a million-person city into linked structural nodes.
High-speed movement would connect the pyramid's stacked districts.
The dimensions rely on ultra-light structural technology beyond practical supply.
The concept remains outside Tokyo's funded planning programme.
The proposal returns through architectural and urban-history exhibitions.
Why it ended
The pyramid remained a corporate future-study without approvals, finance, a site commitment or buildable structural materials.
Last confirmed trace
Engineering illustrations, television visualisations and Shimizu's broader archive of future concepts preserve the proposal.
What it left behind
It became a durable image of Japanese megastructure culture and the gap between calculable geometry and constructible cities.
How we classified it
The proposed archive unit never reached ordinary public access in the form being documented.
The strongest verified milestone maps to documented_concept under Arrival Score V1.
Sources & verification
Last reviewed 2026-08-01. Sources are linked so readers can inspect the evidence directly.