All cities should be able to float.  Should be able to absorb shock.  Should be able to survive the vacuum of Space.  Our future cities should be able to endure lava, solar radiation, and non terrestrial invasion.  Cities should be self sustaining.  Each of the cities having separate areas allocated for housing, education, stores, entertainment, industry, and agriculture with transportation to, from, and throughout.  This Earth is hazardous and will only become more so, if we wait we will be unprepared for reality.  We are currently ants ignorantly building begging for our lives to get kicked over.