New Jersey features a remarkably diverse physical geography for a state of its size. It is bordered by the Atlantic Ocean to the east, the Delaware River and Pennsylvania to the west, New York to the north and northeast, and the Delaware Bay to the south.
The state is typically divided into four distinct physiographic provinces. The Ridge and Valley Appalachian Province in the northwest features rugged ridges and valleys, including the Kittatinny Mountains. Just southeast of this lies the Highlands, a region characterized by flat-topped ridges, deep valleys, and numerous lakes. The Piedmont region spans the central part of the state; it is characterized by rolling hills and is home to the state's largest cities and most densely populated suburbs.
The largest region is the Atlantic Coastal Plain, which covers the entire southern and eastern half of the state. This area is relatively flat and sandy, featuring the globally unique Pine Barrens—a massive, heavily forested ecosystem recognized as an international biosphere reserve. The Coastal Plain also contains the state's famous coastal barrier islands and estuarine marshlands.
