The Outer Barrier, also known as the Long Island and New York City barrier islands, refers to the string of barrier islands that divide the lagoons south of Long Island, New York from the Atlantic Ocean. These islands include Long Beach Barrier Island, Barnum Island, Jones Beach Island, Fire Island and Westhampton Island. The outer barrier extends 75 miles (121 km) along the South Shore of Long Island, from the Rockaway Peninsula in New York City to the east end of Shinnecock Bay in Suffolk County.

Coney Island is a peninsular neighborhood and entertainment area in the southwestern section of the New York City borough of Brooklyn. The neighborhood is bounded by Brighton Beach to its east, Lower New York Bay to the south and west, and Gravesend to the north and includes the subsection of Sea Gate on its west. More broadly, the Coney Island peninsula consists of Coney Island proper, Brighton Beach, and Manhattan Beach. This was formerly the westernmost of the Outer Barrier islands on the southern shore of Long Island, but in the early 20th century it became a peninsula, connected to the rest of Long Island by land fill.