Robotropolis is a location that appears in the AngieYaz/RoseOfSharon reboot of the Sonic Underground series. Formerly (andm after Robotnik's defeat, currently) known as Mobotropolis,this city was once the glorious capital of Mobius, ruled by King Jules Celeritas, Queen Aleena and their royal family. However, the city was captured during Dr. Robotnik's uprising and became the capital city of the Robotnik Empire, rechristened Robotropolis.
Before Robotnik's takeover, Mobotropolis was a beautiful city with civilization and nature coexisting in perfect harmony. Now a vast city of only both technology and pollution, Robotropolis is a dreary and lifeless metropolis. At the heart of this city of evil lies Robotnik's headquarters, which used to be the Royal Hedgehog Palace (one of several palaces owned by the royals). One particularly characteristic building in the city was reminiscent of a multi-storied pyramid. In addition, the city also held a laboratory for Sir Charles Hedgehog, the queen's brother.
Robotropolis has a sizable amount of de-roboticized inhabitants, namely the nobility and inhabitants in the poorer parts of the city, and has a run-down slum for the underclasses and more upscale areas for the aristocratic elite.
Sir Charles has as well two hideouts in Robotropolis, both hidden under piles of scrap metal. It was in one of these hideouts that Sonic and his siblings were sent to live with their uncle, with Amy Rose Speedington and her family joining them (for a few years at least) along with a baby fox named Miles "Tails" Prower.
Originally, Mobotropolis was a peaceful and beautiful city ruled by King Jules Celeritas and his wife, Queen Aleena. Just one year after the birth of Jules and Aleena's children, Sonic, Manic and Sonia, the aristocrat Dr. Robotnik took over Mobotropolis, along with the rest of Mobius, using his technology. The city was subsequently rechristened Robotropolis, and became the capital of Dr. Ivo Robotnik's global empire.
As the source of Robotnik's money, the aristocrats of Robotropolis were largely ignored, while the less fortunate citizens were roboticized. Forced into hiding, Queen Aleena and her husband fled the city with their children, but returned to leave their children in the care of familial relatives and aristocrats to fulfill the prophecy given by the Oracle of Delphius, which stated their family would one day reunite to form the Council of Five and overthrow Robotnik, restoring Mobius back to peace and prosperity.
Once Robotnik is defeated and peace is restored to Mobius, Mobotropolis is restored to normal, with help from a Robotnik from an alternate Mobius that the soon-to-be-crowned Sonic met on one of his missions.
- A statue of what appears to be the King from the Sonic the Hedgehog television series used to stand in Robotropolis before Robotnik's takeover.
- In look and design, Robotropolis is exactly like the city of the same name in the Sonic the Hedgehog television series.
- Sonia, Sonic and Manic have an apartment in Robotropolis. This apartment is rather large, and has a dormer window (with window seat) where Sonic is sometimes seen looking up at the stars while thinking of his parents.
- Robotropolis/Mobotropolis is often compared to the cities of London and Paris on Earth, as well as the city of Crystal Tokyo from the Sailor Moon anime, as they are the main cities from which royal families ruled their kingdoms.
- The latter comparison is from the fact that in that series Crystal Tokyo, like Mobotropolis, is just the main city that is part of a worldwide kingdom.