There are many big cities in the U.S.A., but just a few are interesting enough to be distinguished. Philadelphia, Pennsylvania is one of them, because of its historic district, an old part of the town that was partially preserved. Philadelphia is best known as the birthplace of the United States, a place where both the United States Declaration of Independence and the United States Constitution were debated and signed. The Liberty Bell, Independence Hall, and Rocky Balboa (character from the Sylvester Stallone's 1976 movie Rocky) are not only the symbols of Philadelphia, but also well known American icons.
