Old city of Philadelphia refers to the area from Second Street to Sixth Street in the east, from Chestnut Street to Race Street in the south. There are horse-drawn carriages with small naps, quiet old houses, exquisite shops with literary tones, isolated the hustle and bustle of the city, exuding the warm taste of life. The first stop is Elfreth’s Alley, the oldest residential street in American history dating back to the early 18th century. The old town street scene is like an American coffee, simple on the surface, and every mouthful is a concentrated taste of good time under the moistening of time. Every house, every window, seems to be able to smell the rich aroma of history.