what metropolitan area that you've been to has the most poorly define ghettoes?

[freepcrusher]

By that I mean an area where a tony neighborhood is only a few blocks away from a blighted slum.
In my opinion, it is largely a sunbelt phenom.

I would say that LA, Houston and the Tri County region in SoFla have the worst. I guess you could also say the IE is like that but I'll lump it in with the same region as LA.