Why it looks like this

The name is literal: Phoenix rose on the remains of a vanished civilization. The Hohokam farmed the Salt River Valley for centuries using hundreds of kilometres of hand-dug canals; when settlers arrived in the 1860s they cleaned out and reused the ancient channels, and several of today's working canals still trace Hohokam routes.

On that watered desert the city rolled out one of America's purest grids — major roads every mile, aligned to the compass — which now carpets the valley for tens of kilometres, interrupted only by bare mountains and the canals that made it all possible.