Sky City 1000
Takenaka proposed a kilometre-high stack of fourteen inhabited plateaus for 135,000 people at the peak of Japan's property bubble.
Quick facts
- Existence state
- Never Born
- Peak stage
- documented concept
- Research confidence
- high
- Last verified
What it was
A visionary vertical-city proposal by Takenaka Corporation for Tokyo.
Fourteen dish-shaped plateaus would contain homes, offices, schools, theatres and green space above the metropolis.
Existence timeline
A one-kilometre inhabited tower is proposed for Tokyo.
Large open layers structure the vertical city.
Homes and workplaces for 135,000 people are calculated.
The proposal enters international structural-engineering literature.
Sky City remains a research proposal.
The tower becomes a recurring megastructure case study.
Why it ended
The speculative study was never commissioned or approved for construction.
Last confirmed trace
Published diagrams, engineering literature, models and reference records preserve the design.
What it left behind
Sky City 1000 became one of the best-known Japanese bubble-era explorations of life inside a megastructure.
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.