Star City was an inhabited ring around the Earth in the geostationary orbit, connected to the Equator by four towers. The towers, or 'space elevators' were over thirty six thousand kilometres high and were linked by an inhabited ring. They were constructed in the Third Millenium to accommodate for a bigger population and more space ports, which were built on the ring.
Star City was probably constructed of diamond or buckminster carbon, both incredibly strong carbons. It accommodated for a bigger population than Earth could sustain alone. It also meant that there would be no need for space ports on Earth. Space ships could be constructed and launched in orbit from space ports built on the ring, with materials brought up the ring in the elevators. Star City also made sattelites obsolete because transmissions could be made from the ring. During construction sattelites and space junk were probably cleared as they could threaten the ring and the towers.
Most inhabitants rarely visit Earth and spend most of their time on the ring. The ring links the four towers - the Africa Tower, the Asia Tower, the America Tower and the Pacifica Tower. The Pacifica Tower was still in construction long after the others and many parts of the ring were not inhabited. When inhabitants visited Earth, they took an elevator down one of the towers. Most inhabitants took the inner elevator, which had no views, but there was also an 'observatory' elevator which showed spectacular but vertigo-inducing views of the Earth to those who wanted them. It was quicker to take the inner elevator because the 'observatory' elevator was slowed so that people could have more time to see the views. Food came from the biomes, domes on the ring where food could be grown.