Philadelphia has 1.5 million residents and, following New York, it is the second largest city on the east coast of the USA. It is located in the state of Pennsylvania on the Delaware River. Philadelphia is one of the most important cities in the history of the USA. Numerous historical locations and buildings still bear witness to historical events. In Independence Hall, the Declaration of Independence was signed in 1776, and later, the Constitution - which can be seen at the center in the Independence National Historical Park. In the glass Liberty Bell Pavilion is the bell that was rung to announce the signing of the Declaration of Independence. The Franklin Court museum is located underground. It is at the spot where the house of Benjamin Franklin, one of the USA's founding fathers, stood. Other sites include Pennâ€™s Landing, where William Penn, founder of the state of Pennsylvania, came ashore. Valley Forge National Historical Park in the western part of the city is a significant memorial site of the American Revolutionary War.