East of the Bronx River, the borough is relatively flat and includes four large low peninsulas, or 'necks,' of low-lying land which jut into the waters of the East River and were once saltmarsh: Hunts Point, Clason's Point, Screvin's Neck (Castle Hill Point) and Throgs Neck. The East Bronx has older tenement buildings, low income public housing complexes, and multifamily homes, as well as single family homes. It includes New York City's largest park: Pelham Bay Park along the Westchester-Bronx border.
In what river does the Bronx have 4 peninsulas?
East River