This is about the busy night life of New York City, could be about Los Angeles for that matter - especially around 42nd street.
Some fun facts about the song,"The Zoo":
Bruce Dickinson of Iron Maiden has covered this song.
This was used for a bit by pro wrestling company ECW (Extreme) back in the 90's as the theme song to one of their wrestlers named Bam Bam Bigelow.
The Scorpions live in Berlin perform "The Zoo" from 1991.