2. It limits the north with the state of New York, the south with Maryland and Western Virginia, the west with Ohio, the east with New Jersey and the northwest with the Erie lake.
5. Another of the populated cities of Pennsylvania is Pittsburgh.
6. Allentown is a city located in the county of County of Lehigh. After Philadelphia and of Pittsburgh, it is the third more populated city of Pennsylvania.
7. The Pocono Mountains region is a mountainous region of about 2,400 square miles (6,200 km²) located in northeastern Pennsylvania
8. The Delaware river has a length of 579 km and drains an area of 36,568 km ².
9. The Allegheny river has a length of 523 km. Their main affluents are the Clarion river, the Kiskiminetas river and the French stream .