New Jersey can be thought of as five regions, based on natural geography and population. Northeastern New Jersey, the Gateway Region, lies within the New York metropolitan area, and some residents commute to the city to work. Northwestern New Jersey, or the "Skylands", is, compared to the northeast, more wooded, rural, and mountainous, but still a popular place to live. The "Shore" along the Atlantic Coast in the southeast has its own residence and lifestyle characteristics owing to the ocean. The southwest is within Metropolitan Philadelphia, and is included in the Delaware Valley. The fifth region is the Pine Barrens in the interior of the southern part and is covered rather extensively by mixed pine and oak forest, and as such has a much lower population density than much of the rest of the state.
Pennsylvania is 170 miles (274 km) north to south and 283 miles (455 km) east to west. Of a total 46,055 square miles (119,282 km2), 44,817 square miles (116,075 km2) are land, 490 square miles (1,269 km2) are inland waters and 749 square miles (1,940 km2) are waters in Lake Erie. It is the 33rd largest state in the United States.