Introduction to Fengzhi Chengenfang in Back Street: Historically, Changjia buildings were mainly composed of Nanchang Street and Beichang Street, collectively known as "Changjia Two Streets". Now only some buildings in Beichang have been preserved. Fengzhi Chengenfang, a stone archway with four pillars and three doors across the back street, was erected by the imperial decree of Emperor Jiaqing. The emperor's favor to the Chang family engraved on the plaque all came from a donation made by Chang Bingru to the country. From this, it is not difficult to infer the economic strength of the Chang family at that time.