i find urban agriculture to be really interesting, Urban agriculture can reflect varying levels of economic and social development
Ive never lived in a big city before, but I can understand what you are saying.   I am amazed at how they build the buildings
In the global north, it often takes the form of a social movement for sustainable communities
so do people trade the different things that they grow?
i am prety sure there is trading involved in this kind of things
i was never good at growing things.  i always kill plants
that is not good hahah,  In either case, more direct access to fresh vegetables, fruits, and meat products through urban agriculture 
Is this a popular thing? i dont think ive heard of it being peopluar in big cities
yes im pretty sure it has been around for a while
hmm, maybe I should try it out in my neighborhood