The Staunton Island City Hall is a building located between Torrington and Newport next to the Callahan Bridge on Staunton Island, Liberty City in Grand Theft Auto III and Grand Theft Auto: Liberty City Stories. It is initially referred to as a City Hall in the files, but is also used as a museum during sidemissions in both games.
The city hall is made up of the municipal building which is a large, ornate structure, possibly drawing influences from the real-life Federal Hall in New York City. As mentioned above, the city hall is only one section and not a neighborhood, but still is a very important place in Staunton Island.
In the official website of GTA III is mentioned as the City Hall of the city, while in GTA Liberty City Stories is called the "Liberty City Museum" during the mission See the Sight Before Your Flight (sight 8) and in GTA III taxi missions it is also called "museum".