It's possible to look at this picture and consider it to be beautiful. These were once barren hills, and now they've been completely adapted to suit human life. Homes, offices, schools, and hospitals seem to stretch on forever. It looks like a Photoshop creation, but it isn't. This is really what Mexico City looks like if you catch it from the right angle.
What you won't see anywhere in the picture is a park, or any areas of green land at all. The town planners in the city have just kept on building and building until there's nowhere else to go. Whereas in other parts of the world it's the custom to build up when you run out of space to build out, Mexico City has just carried on wedging houses in wherever it can find enough yards to do it. It's one of the world's most overpopulated residential areas. Due to the lack of trees and green spaces, it also has some of the worst air quality.