Ed McBain's "87th Precinct" series of novels is set in which fictional US city?

The "87th Precinct" is a series of police procedural novels and stories written by Ed McBain (pseudonym of Evan Hunter). McBain's "87th Precinct" works have been often adapted, sometimes loosely, into films and television drama.

The series is based on the work of the police detective squad of the 87th Precinct in the central district of Isola, a large fictional city based on New York City. Most of the "87th Precinct" novels feature a significant role for McBain's leading character, Detective 2nd Grade Stephen Louis "Steve" Carella. All of them begin with the same disclaimer: "The city in these pages is imaginary. The people, the places are all fictitious. Only the police routine is based on established investigatory technique."

Isola is both the name of the entire city and of the central district of the city (it fulfils the role of the borough of Manhattan within New York City). Other districts in McBain's fictionalized version of Manhattan broadly correspond to NYC's other four boroughs, Bethtown standing in for Brooklyn, Majesta representing Queens, Riverhead substituting for the Bronx, and Calm's Point for Staten Island.