Entering the gate of the Yuxu Palace, one is greeted by a large courtyard covering over forty mu. The ground here is paved with bluestone, spacious and well-organized. Back in the day, this place was not only where officials from the imperial court came to pay homage to Emperor Zhenwu on Wudang Mountain, but also where Wudang Taoism set up altars and held religious ceremonies. After the great renovation of Wudang during the Yongle period of the Ming Dynasty, successive imperial courts frequently held the highest-level and largest-scale sacrificial ceremonies and rituals here. This square-style courtyard seems to have been specially designed and built for this purpose. According to local Chronicles, after the emperor ascended the throne in the Ming Dynasty, he would send ministers and eunuchs from the inner palace to hold the "Golden Seal Grand Ceremony" here. The ritual of the ceremony would take seven days and nights to complete. The Tang Dynasty poet Wang Wei once wrote in a poem: "The jade capital moves a great statue, and the golden seal script gathers all the immortals." It is said that the functions of the Golden Seal ritual are numerous. Among them, the golden seal ritual of the Upper Yuan Dynasty helps the king and emperor to stabilize the state and protect all living beings, eliminate natural disasters, ward off calamities, control the fate of disasters, and pacify the mountains and rivers, etc. The venue for the ritual is very grand, with four altars: the outer, middle, inner and square ones. The Taoists were divided into groups. According to the different seasons, they lit 500 to 900 lamps, and nine lamps each one zhang and nine feet long were lit from the ground. They held letters and delivered words on behalf of the ministers, ascended to the middle altar and the Heavenly Gate, offered incense from the five directions, knelt and paid homage to the ten directions, and read the true texts from the five directions... Wait a moment. Such a grand scene and complicated rituals could not have been accomplished without a large venue. Careful visitors can still see the flagpole stones, worship stones and the stone caves carved for placing flags and banners here. Of course, the grand scene of the sacrificial ceremony can only be imagined by us.