North Brother Island, East River, New York City, United States

North Brother Island is a small island in the East River situated between the Bronx and Riker's Island, New York City. Once the site of a hospital, it is now uninhabited and designated as a bird sanctuary. It measures approximately 400 m by 250 m. Its smaller companion, South Brother Island, is a short distance away. Together, the two Brother Islands, North and South, have a land area of 20.12 acres (81,400 m2).