[balletomane]

I guess these could be considered conceptual cities that actually started to see their vision unfold, only for it to fail...

California City by Nat Mendelsohn
It was envisioned that the city would one day rival Los Angeles in size, but it had a little under 15,000 residents in the 2010 census.

https://www.good.is/articles/ghost-t...alifornia-city

Salton City by Penn Philips
During its initial boom period it sold 32,000 lots, but in 2010 its population was only over 3,000.

http://www.greetingsfromsaltonsea.com/saltoncity.html

Although the developers of today seem not to have learned the mistakes of the past, Travertine Point, a proposed city of 40,000 not far from Salton City.

https://la.curbed.com/2011/5/27/1046...n-sea-shores#5