I was just coming back into the thread to say I'd found it, and you got there first, that's truly impressive given how little I could remember.
http://en.wikipedia.org/wiki/The_Iron_Tower
I'll have to reread them.
This thread is now about books you read as a child or teen that you'd like to read again.
There was one other book that I'd read that I'll have to dig out sometime, it was about a girl who got left alone on earth after a nuclear/biological war (can't remember exactly), and how she finds others and such. I remember it because it was written in kind of a weird shorthand, no vowels, so it was weird to read.
Ah found it:
http://en.wikipedia.org/wiki/Emergence_(novel)