Mexico City's 20 million residents live in neighborhoods built on all kinds of plans -- see these aerial views of neighborhoods developed according to: the colonial center plan built on the foundations of the Aztec capital Tenochtitlan, geometric plans, Ciudad Neza with greenspace confined within mega-blocks, organic neighborhood plans for the rich, extreme grids for the poor, Modernist plans, etc. Fantastic!
On [polis] a collaborative blog about cities across the globe.