The 150 miles Between Phoenix and Tucson metros.
The towns of Casa Grande, Coolidge, Florence, Maricopa, Eloy. For 40 years people have been predicting it to be developed and Phx-Tucson will be one single metro but we aren't really any closer to that today than we were 40 years ago.
Almost the whole stretch looks like this:
Its mostly farms, some Disrtro centers, an airplane graveyard, failed megaprojects and recently some big time manufacturing gains, Lucid, Nikola, Kholor, P&G all have or are building major factories in this area which is likely to draw a lot of new population who will be able to afford the suburban dream on manufacturing salaries so maybe we will see the cities finally connect into the long predicted "Sun Corridor"