Things I Like - Odds & Ends

I was wandering around the internets the other day and these sculptures caught my eye. Can you figure out what they represent? Obviously, they're cities - but what specific feature?

Mumbai

Mexico City
Cairo

London

Photographs: Nick Turner

These are 'density models' at the Tate Modern in London, depictions of a city's population in 3-D. As reviewed in CR,

"Overcrowding never looked so attractive...The plywood structures were created by a team of designers and architects at the London School Of Economics, led by Professor Richard Burdett. The models are shaped around the outlines of each city, with each layer of plywood representing an extra 200 people per square kilometer."

This photo gives a feel for the size of the exhibit relative to the room
Photograph: Ed Reeve

Read the complete review of the installation at CR (Creative Review) - unfortunately, the exhibit was only at the Tate through August 27th of last year.
http://www.creativereview.co.uk/crblog/global-cities-at-tate-modern/