I built a 3D version of Seoul with GPT-6 Astra — and it reached 330K+ views on X

Hi Product Hunt 👋

I’ve been experimenting with a simple idea: What if you could explore Seoul as a living 3D city instead of a flat map?

That experiment became Seoul in 3D Miniature for GPT-6 Atlas. It started as a 3D visualization of Seoul, but each iteration created a new question. Once the city existed, I wanted to see how people move through it. so I added subway routes. Then came buses. Transportation led to landmarks, hotels, cultural sites, tourism information, multilingual UI, currencies, weather, seasons, and day/night experiences.

The project now visualizes more than 267,000 buildings across Seoul in one interactive experience. I built it through repeated iterations with GPT-6 Astra — not as a one-shot code generation experiment, but as an ongoing product and engineering workflow.

I would define a requirement, test the result, find problems, change the requirement, debug it, and continue building.

When I shared a demo on X, it unexpectedly reached 330K+ views, which made me realize there was real curiosity around experiencing cities this way. Now I’m launching it on Product Hunt and would genuinely love feedback from other builders.

If you were exploring a city in 3D, what would matter most to you?

Transportation, local places, tourism, real-time city data, weather — or something completely different?

Would love to hear your ideas. 🏙️ You can try this right now: https://seoul-3d-atlas-new.synabreu.chatgpt.site/