Big City is a future city in Antarctica in the fictional universe of DC Comics

DC Comics

DC Comics, Inc. is one of the largest and most successful companies operating in the market for American comic books and related media. It is the publishing unit of DC Entertainment a company of Warner Bros. Entertainment, which itself is owned by Time Warner...

. Because of global warming

Global warming

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

, Antarctica in the future is covered with cities. One of these cities was magnified in size by Bizarro Brainiac

Bizarro Brainiac

Bizarro Brainiac is a character in DC Comics. Bizarro #1 created this doppelganger of Brainiac to live on Bizarro World. Since Brainiac shrank the city of Kandor, his Bizarro counterpart felt compelled to do the opposite, and expanded a city in Antarctica, creating Big City.ReferencesBizarro...

 as he seeks to reverse what Brainiac

Brainiac (comics)

Brainiac is a fictional character that appears in comic books published by DC Comics. The character first appeared in Action Comics #242 , and was created by Otto Binder and Al Plastino....

 did by shrinking Kandor

Kandor

Kandor is the name of the former capital city of the fictional planet Krypton in the DC Universe. It is best known for being stolen and miniaturized by the supervillain Brainiac...

. Big City was once called McMurdo City and the people left behind are the protectors. Big City is also the home to Colossal Boy.

Source: Supergirl and the Legion of Super-Heroes, issue #20, September 2006.

See also:
Antarcto

Big City is also the fictional setting of the "Dynomutt and Blue Falcon" cartoon.