Introduction to the Corridor: The corridor is located in the northwest of the Fourth Teaching Hall. It is a wooden structure with a nine-curved shape, more than 60 meters long, and is called the "Nine-curved Corridor" because of the support for the king on both sides. There are three small pavilions at the north and south ends of the corridor and in the middle. The pavilions at both ends have the same structure, about 5 meters high and hexagonal. The corners of the pavilion are protruded with brackets. The top of the pavilion is topped with a stone lotus seat with a gourd-shaped dew tray. The waist pavilion in the middle of the corridor is octagonal and about 10 meters high. There are four dragon heads carved on the top of the pavilion, which is called the "Polygonal Dragon Head Pavilion".