Sun glints off the sleek cities of Multus Metallum in a thousand refracted rays. Like a constellation set into the landscape, these cities shine with all the brightness of the stars. Reflected light is but the excess; those photons that escape being consumed and converted. Within the cities structures are lined with a combination of reflective and light absorbent surfaces. These surfaces are mounted on plates of the most advanced alloys; designed for light weight without loss of strength. Each plate is attached to a robotic arm controlled by the City Central AI and used in coordination to capture the precious solar energy that streams down like mana from the heavens.
Between towering skyscrapers opaque tubes crisscross the air across the cities. They connect the many buildings, looking like great rectangular octopi clasping tentacles, or like a thin cobweb of dark thread hung upon gleaming monoliths of metal. Within are the tubecars; large spherical structures that are controlled and propelled by clever manipulation of magnetics and are designed for quick and comfortable travel.
Below the surface lie the great rails linking each city directly. Thermal energy harnessed by pillars sunk deep within the earth is gathered into the rails and used to power the vast cargo trains that traverse them. Only a fraction of this energy is used by the trains, the rest is transported as cargo; stored within large battery cars during the interim.
Above ground, spanning between the cities, spread raised highways of darkened metal. Hover-vehicles cross these expanses, taking citizens between the cities and to lesser destinations across the land. Use of magnetics within the highways and the vehicles controls the flow of traffic and keeps the hover-craft afloat. AI systems within the active vehicles sync to the highway AI, which in turn coordinates with the collective of city AIs that organize and maintain the day-to-day functionality of civilization.