New York city vs Hong Kong sar. (Maybe I am exaggerating - difference in density is about factor 2.5)

Even then, the Hong Kong Administrative Region has about 430 square miles of land, compared to New York City’s 300 square miles of land. This is a more reasonable comparison than New York States 55,000 square miles of land. (The city of Hong Kong itself is more comparable in size to the Manhattan Island portion of New York City)