Having grown up in relatively closed city of Omsk, Russia, I knew (like every other boy of my age) the exact coordinates of probable nuclear strikes in case of war (ICBM silos perimeter, tank production plant officialy known as transport machinery plant, nuclear weapons maintenance plants etc.) All of which were supposedly secret, but everyone knew everything anyway.
² My friend helped me with the papers. I don't remember exactly, but simply saying "I want to visit my friends" is not enough. It's more complicated than that.
Apparently there were lots of kids with badges, many sport venues. His guess was a some sort of talent building city for olympics.
edit: Here it is through translate (haven't checked how bad it is) https://translate.google.com/translate?sl=auto&tl=en&u=http%...
Perhaps a more interesting case is Centralia PA.
There were several areas where the road was damaged, and it was clear that it wouldn't be wise to put too much weight over top, but there are still people living in the area.
Or it could just be that whoever added the content has Russia-centric knowledge or interests and contributed that. Wikipedia knowingly suffers from systematic bias  and many articles will have a tag like this one  for being too US-centric. The problem with addressing that is that most editors are American and don't really have access to other language reliable sources. Though in this case the sources are in English so it could just be that English-language sources all focus on that area.
For example, the articles for the regions in China don't mention that they're closed cities.
And for the current closed cities in Russia, their articles just say that they're closed in the first sentence and don't reference it again.
I think there's a lot of scope to develop the article and associated pages with more information.
Louisiana State prison (aka Angola) is a closed city imho. It has a golf course, farms, an air strip and cemetery.
My point is that wikipedia gives the impression that such cities are the mark of oppressive or secretive regimes, listing only a handful of formerly-closed cities in the US. And those were all relate in some way to the Manhattan project. But there are plenty of other closed cities in the US of today ... so um well ... read into that what you will.
It's easy to get to the Louisiana State prison, just commit a crime appropriate to the security level of the prison and make going to that prison part of your plea bargain.
I can't tell what you're trying to say. Cities are never able to meet the needs of their inhabitants; they need to import food. In that sense, this would be an extremely odd way to define "cities". But you mention "commerce" -- if you assume that purchasing imported necessities counts as "meeting the needs of the inhabitants", I would think that everywhere on earth is "large enough" to do so.
Also, without any uncomfortable analysis into what should and shouldn't count, a single peasant household definitely is large enough to meet the needs of its inhabitants in the same sense, whatever that is, that any urban area can. (Even peasant households -- and villages -- ordinarily purchase iron and salt rather than producing them.) Peasants, though, are generally considered the opposite of cities.
Likewise an army base with a basic training or advanced training school battalion isn't very free for new recruits but the cadre and soldiers unrelated to the basic training battalion may very well outnumber the recruits and live in a reasonably nice private closed city.
But don't generally live in the prison. The residents of the prison are not free citizens.
> Likewise an army base with a basic training or advanced training school battalion isn't very free for new recruits but the cadre and soldiers unrelated to the basic training battalion may very well outnumber the recruits and live in a reasonably nice private closed city.
US military bases are probably better examples or approximations of the idea of a closed city than US prisons.
It would seem much more difficult to provide security/surveillance details for critical personnel (to prevent assassination or compromise by foreign agents) and their families (to prevent kidnap/extortion) living in bustling open cities, than to provide housing in secure facilities where such threats cannot even get near them.
If I were (say) Iran, I might not want my nuclear scientists living among the masses.
AKA factory not found.