Long Island is a natural airfield. The central area of Long Islandas Nassau Countyaknown as the Hempstead Plainsais the only natural prairie east of the Allegheny Mountains. The island itself is ideally placed at the eastern edge of the United States, adjacent to its most populous city. In fact, nowhere else in America has so much aviation activity been confined to such a relatively small geographic area. The many record-setting and historic flights and the aviation companies that were developed here have helped place Long Island on the aviation map.