A no longer extant dystopian future slum in Hong Kong: Highrises of Anarchy. Well not really anarchy; the Triads kept a sort of order. A tiny real life Megacity 1.
If I calculate correctly, 33,000 residents on 2.6 hectares (26000 square meter) equals more than a million people on a square kilometer… For comparison: Typical German inner city with 5 story buildings should be about 10,000 per square kilometer.
Guess they didn’t have huge apartments in there. Amazing how sinoid people get along under such conditions.
h/t Michael Kumpmann, in a comment.