Philadelphia is the earliest capital of the United States, and the old city refers to the one square kilometer extension from the center of Independence Square, basically within this range, every step of the road can see a historical building very dense. If you drive, you will also feel that sometimes there is traffic jam. This historic city has witnessed the historical development of the entire United States. Most places are free to enter. It is quite good. The tourist service is also very good. The planning and route are relatively complete.