Intrepid Cities: Skylines player inthoughtwelive has recreated downtown Seattle using 49,152 buildings, at which point the building limit put an end to his architectural dreams. I haven't been to Seattle—this could be a replica Mombasa for all I know—but Google Maps seems to corroborate things.

Starting with a template by Tanis_2589, inthoughtwelive "redid all the highways, and then eyeballed the rest using Google Earth as a reference". Traffic lights had to be forcibly disabled so as to avoid a traffic jam of apocalyptic proportions.