[brasso]

How do you know your Runner has hit "Leet" status?
When he no longer wears body armor & combat boots but instead is so good that he runs in cargo shorts & flip flops.

Pmsl XD

[BetaCAV]

I've always pictured the barrens as the opposite of urban renewal. Abandoned buildings in the process of being run (further) down by the squatters that live in them, until they get torn down/apart for materials to build huts in nearby vacant lots, with the occasional post-apocalyptic walled community that either provides it's own security, or has made some "arrangement" with a local gang to do it for them. Everything is free, and it can be yours for as long as you can hold onto it... but there's not enough of it to go around, whatever "it" happens to be.

"Little Somalia" might be a good thumbnail, though a bit 5th-world-y. Everyone might visualize it a bit differently, but it tells them what they need for their character to know about living there. Beer and ammo are good to trade with, perhaps better than Nuyen. Toilet paper, too -- even the reusable/recycleable plastic kind. 

[The Wyrm Ouroboros]

Actually, I got the sense that the guy with the assault rifle is the only competent one there.  There's 'lookit, I got GUNZ!!' with the pistols on the right, then the other three - two who think they should wear frickin' boxer shorts, all three of whom think that sticking pistols into their waistbands (one with an extended clip!!) is cool, and that covering their faces with bandanas is going to prove they got brains.  Naah - give me AR guy any day of the week.

[Sithlis]

Actually the one that worries me is the guy with the revolver, chances are the rest of those guns haven't seen a lick of cleaning.

[Danny Montanny]

District B13 or the new American version, Brick Mansions might fit the bill. Some parts might be as bad as Chernobyl I'd think.

[Deadborder]

http://detroiturbex.com/content/index.html

This is pretty much my go-to site for urban ruins, even if most of it is just the one city. However, it's also pretty much what I imagine much of the Barrens look like, both in Seattle and other similar areas in other cities. Ironically, given its descriptions as being "the wealthiest and most prosperous city in the UCAS", I'd imagine that 6th World Detroit doesn't look like this.

[iduno]

I watched an episode from the Gangland documentary about Cabrini Green that described the barrens nicely.

Old cheap apartments that had no real control over them. Gangs formed for mutual protection, then for money. The apartments were taken over by the gangs, then fortified to keep out the police. The gangs had free reign over their turf, but had to keep civilians safe and relatively happy.

[Aryeonos]

I was going to bring up District 13, or modern day shinjuku in its rougher parts. Thats what I`d call the civilised parts of the barens, as it gets worse you have places like Kowloon (now demolished)..

[Tarislar]

Brick Mansions might fit the bill.

I saw this pop up & net flix & disregarded it till I saw your post.
Watched it last night.
It might not be the best example of the barrens ever, but it was pretty good, & it very much works as a section of them taken over by a large gang.
Too much parkor stuff in that movie for my taste but it was a nice background for a SR setting.