But yet people think the heart of Paris, Rome or even Hong Kong are wonderful. Build the neighborhoods correctly and beautifully and the city can continue indefinitely

The Paris metro area (Aire d'attraction des villes) is only ~7,300 square miles, with the city proper only being 41 square miles. They're talking 31,400 square miles of essentially Paris proper.

So imagine the city of Paris, but stretched about 766x. If you want to include the whole metro area, then ~4.3x

Hong Kong is ~431 square miles. So about 73 Hong Kongs. But not really, because only ~25% of that area is actually urban. So more like 291x the urban area of HK.

Just because the scale doesn’t exist today doesn’t mean it can’t exist or wouldn’t be desired if built.

500 years ago people would have thought any of the cities described were impossible.

> doesn’t mean it can’t exist or wouldn’t be desired if built.

I never said anything contrary to that. I'm just saying it would be wild to see a metro area that size with that high of average development.

The above commenter suggested:

> It might literally be nowhere in the US.

It's definitely not a thing in the US. It's almost certainly not a thing in Europe either, but I'm open to being proven wrong there. It might exist in China, I haven't looked. A 100mi radius circle is massive in area. Pies are squared, if you get my point.

I'm actually inclined to believe it was a typo for 10 mile radius.