Nadim Karam obviously read "Invisible Cities" by Italo Calvino. If he didn't, then this is just a crazy coincidence. This "city in the sky" is exactly the city called "baucus" (sp?) in Calvino's book. It is a very pleasant read which paves a nice path to the surreal imagination.
http://tal.forum2.org/invis
Its not in the sky but it was done first
http://www.dillerscofidio.com/blur.html