Coney Island is a peninsular residential neighborhood, beach, and leisure/entertainment destination of Long Island on the Coney Island Channel, which is part of the Lower Bay in the southwestern part of the borough of Brooklyn in New York City. Coney Island was formerly the westernmost of the Outer Barrier islands on Long Island's southern shore, but in the early 20th century it became connected to the rest of Long Island by land fill. The residential portion of the peninsula is a community of 60,000 people in its western part, with Sea Gate to its west, Brighton Beach and Manhattan Beach to its east, the Lower Bay to the south, and Gravesend to the north. Coney Island was originally part of the colonial town of Gravesend. By the mid-19th century, it became a seaside resort, and by the late 19th century, amusement parks were also built at the location. The attractions reached a historical peak during the first half of the 20th century, declining in popularity after World War II and following years of neglect. The area was revitalized with the opening of the MCU Park in 2001 and several amusement rides in the 2010s.