This is a city of the year 2619. Thanks to the UN Agricultural Availability resolution 500 years earlier, every patch of arable land has been claimed for automated farming. Humans were forced to build new cities in the U-classified areas(Unsuitable for resource production). Millions of square meters of city, more than 90% of all buildings ever built, were razed by the reform, leaving only landmark buildings such as the Empire State Building, the Eiffel Tower and Brandenburger Tor, to mention just a few. Many of these have been moved to the U-zones, where they attract millions of visitors.
After a while, the cities where getting so dense that green areas and parks where almost gone. Many cities solved this by constructing platforms on top of the skyscrapers. On these, they put parks and plazas, but also government buildings, and in some places, luxury housing. Most cities ended up looking like this one: A solid block of overlapping skyscrapers, with canyons to let light and air in. Of course, not everyone will get a room with a view, or even a window.
Deep underground, fusion reactors supply mankind with limitless electricity, enabling a tecnocratic utopia of sorts, where manual work is all done by robots. If you were to complain about anything, it would be the lack of space.
As you can see, I've only finished the first canyon. Hopefully I will finish them all and add some surroundings. I also need to create some nicer parks on the platforms. Thanks to toyota74 for the inspiration to continue on this old project!