Coruscant (pronounced /'kɔɹəsɑnt/), known in antiquity as Notron, also known as Imperial Center, was a planet located in the Galactic Core. It was generally agreed that Coruscant was the most politically important world in the history of the galaxy, and it was the capital of the Galactic Republic, and later that of the Galactic Empire.
Over centuries, the planted developed into an ecumenopolis, with a total of 5,127 levels of city built up from the crust by the time of the Clone Wars. The actual planet-wide metropolis of Coruscant was called Galactic City. Under the Galactic Republic, the names Republic City or the City of Spires were also used to reference the city. It was also called Imperial City under the Galactic Empire. However, in practice, Galactic City and its other names were sometimes applied to the Senate District, the central government center and de facto capital of Coruscant.
Coruscant was a planet located in the Core Worlds. Located at the intersection of numerous major hyperlanes, including the Perlemian Trade Route, the Corellian Run, the Metellos Trade Route, the Koros Trunk Line, and the Leisure Corridor, its hyperspace coordinates were (0,0,0) which effectively made it the center of the galaxy. These coordinates also inspired the planet's military designation, "triple zero" or "Zero Zero Zero," though the actual galactic center was located in the Deep Core. As the de jure center of the galaxy, however, Coruscant was generally agreed to be the most important planet throughout most of galactic history, as well as being one of the wealthiest due to its advantageous location.
Coruscant was known to have the tallest buildings in the Galaxy. Coruscanti skyscrapers dwarfed all the original natural features, including mountains, as well as floors of oceans which once covered a large portion of Coruscant's surface. Areas of Galactic City were broken up into 5,127 levels which were then divided into megablocks, blocks, and subblocks. Coruscant itself was divided into quadrants, which were divided into zones. Below the skyscrapers was Coruscant's undercity, where sunlight never reached. Artificial lighting illuminated these lower levels and advertisement holograms could be seen everywhere. There were numerous establishments for entertainment, catering to a myriad of alien species. The residents were collectively referred to as Twilighters.
Coruscant was once a world mostly covered in oceans. However, all natural bodies of water were drained and stored in vast caverns beneath the city as a result of years of overpopulation. The only body of water visible was the artificial Western Sea, with many artificially-created islands floating on it, used by tourists on holidays.
With no other bodies of water available to feed and water its trillion inhabitants, Coruscant's architects, along with many others from around the galaxy, worked together to build a self-contained eco-system in the massive buildings set all over the planet. Polar cap stations also melted ice and distributed water throughout the planet-wide city through a complex series of pipes.