Mega-City One is a huge fictional city-state covering much of what is now the Eastern United States in the Judge Dredd comic book series. The exact boundaries of the city depend on which artist has drawn the story. The city seems to have grown outward from the present-day Northeast megalopolis, extending down to the Atlanta metropolitan area southwards, and the Quebec City-Windsor Corridor northwards.
The Architects Journal placed it at #1 in their list of "comic book cities."
Read more about Mega-City One: Development, Description, City Blocks, Law, Government, Crimes, Leisure, Transit Systems, History, Other Cities Mentioned in Judge Dredd