Does it have to be a city, could it not just be existance?
An astral world has an appeal, lots of pretty colours, floating, feelings and emotion.
No need for food as it would just be the soul that travels around, unless souls can eat colour, i think i'd eat mainly turquoise.
And souls could merge or drift through each other, sensation intensity riot.
Oh and i'd like to be this girl.
I'm not sure how long i could live in an astral world but it would def be fun flying.