>That is: you can find plenty of places that are denser, but they are
>almost all smaller.
Ok. Now I get it.
Changing the subject, I've been reading Mike Davis's "Planet of Slums" and I was surprised to find no African cities on that wiki density list. But we're talking different kinds of growth. Davis writes "Indeed, in many cases rural people no longer have to migrate to the city: it migrates to them."
Here's another list, with "agglomeration" as the qualifier rather than density:
http://en.wikipedia.org/wiki/List_of_metropolitan_areas_in_Africa