(Tokyo- Image Link)
Megacities aren't just settings for sci-fi novels or places where Judges like Dredd enforce the law- they're massive cities like Tokyo, Delhi or Shanghai where more than 10 million people live in a space never meant to hold so many people.
(Seoul - Image Link)
And when the crowding gets crazy in the megacity builders start building straight up into the sky, erecting the massive buildings which will house millions.
(Hong Kong - Image Link)
It's not hard to find the residential centers in a major city, just head to the edge of town far from the tourist attractions and look for the hive of identical structures the tourism department doesn't want you to see.
(London - Image Link)