<P> 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 km), 44,817 square miles (116,075 km) are land, 490 square miles (1,269 km) are inland waters, and 749 square miles (1,940 km) are waters in Lake Erie . It is the 33rd - largest state in the United States . Pennsylvania has 51 miles (82 km) of coastline along Lake Erie and 57 miles (92 km) of shoreline along the Delaware Estuary . </P> <P> The boundaries of the state are the Mason--Dixon line (39 ° 43' N) to the south, the Twelve - Mile Circle on the Pennsylvania - Delaware border, the Delaware River to the east, 80 ° 31' W to the west and the 42 ° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie . </P> <P> Cities include Philadelphia, Reading, Lebanon and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown, Bethlehem, and Easton in the central east (known as the Lehigh Valley). The northeast includes the former anthracite coal mining communities of Scranton, Wilkes - Barre, Pittston City (Greater Pittston), and Hazleton . Erie is located in the northwest . Williamsport serves as the commonwealth's north - central region, with York and the state capital Harrisburg on the Susquehanna River in the east - central region of the Commonwealth and Altoona and Johnstown in the west - central region . </P> <P> The state has 5 regions, namely the Allegheny Plateau, Ridge and Valley, Atlantic Coastal Plain, Piedmont, and the Erie Plain . </P>

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