The Great Lawn and Turtle Pond are two connected features of Central Park in Manhattan, New York City, United States. The lawn and pond are located on the site of a former reservoir for the Croton Aqueduct system which was infilled during the early 20th century. The pond, originally known as Belvedere Lake, abuts Belvedere Castle as well as the Delacorte Theater, and contains a variety of turtles and fish. The lawn is composed of 14 acres (5.7 ha) of oval-shaped land, which is used not only for sports but also for concerts.