Introduction to the inner courtyard: When the Cao family was at its peak, they built a number of large and magnificent houses in Beigu Village, such as Wugui Hall, Huaiyi Hall, Fushan Hall, and San There are many halls, etc., especially the four courtyards built in the shapes of "Fu", "Lu", "Shou" and "Xi" are the most representative. The surviving "Shou" house is the name of a branch of the Cao family. It is customarily called the "Sanduotang" with the contents of more blessings, more longevity and more men.