Geography. New York City is composed of five boroughs. While Manhattan and Staten Island are islands, Brooklyn and Queens are geographically part of Long Island, and the Bronx is attached to the US mainland.

Yes, Manhattan is geographically an island, though the borough of Manhattan includes several smaller islands and even a small piece of the mainland. The main island of Manhattan is bounded by the Hudson River to the west, the East River to the east, and the Harlem River to the north. These bodies of water completely separate it from the Bronx, Queens, Brooklyn, and New Jersey. However, the political boundaries of the Borough of Manhattan are slightly more complex. It includes Roosevelt Island, U Thant Island, and Randalls and Wards Islands in the East River, as well as Liberty Island and Governors Island in New York Harbor. Interestingly, there is one part of the borough that is not on an island: the neighborhood of Marble Hill. Originally part of the main island, it was cut off by the construction of the Harlem River Ship Canal in 1895 and eventually physically connected to the Bronx mainland via landfill. Despite this one mainland exception, the heart of the "City" is a true island, which is why almost every entrance into Manhattan requires crossing a bridge or passing through a tunnel.