"Free your stomach, but just have a good sleep." "Guan Shi Yu, don't rise eastward; Hong Lun, don't fall westward." " In the vast river of Chinese history, there is an extraordinary person who has been recorded in history for his sleep and has enjoyed good health and a long life because of his long sleep. He is a poet, a Taoist scholar and a health preservation expert. Today, between the inner and outer gable walls leading from the Imperial Scripture Hall to the Bagua Pavilion in the South Rock Palace of Wudang Mountain, his two large characters "Fu" and "Shou" are still engraved. Because it is said to have been written by him while he was sleeping, it is also called "Sleeping for Happiness and Longevity", which implies the Taoist idea of happiness, longevity and health care. Chen Tuan, a renowned Taoist priest of the Northern Song Dynasty, grew up in the Later Tang Dynasty during the Five Dynasties and Ten Kingdoms period. It is said that during his middle years, he lived in seclusion at Jiushi Rock on Wudang Mountain for a long time and practiced fasting and meditation there for more than 20 years. Whenever he goes to sleep, he often stays awake for over 100 days and is renowned for the "Hibernating Dragon Sleeping Method". His complexion was rosy and his movements were like those of a divine being, earning him the title of "Sleeping Immortal" by later generations. So, where is Jiushi Rock located? Why did Chen Tuan live in seclusion here? Recently, a natural landscape investigation team from Wudang Mountain visited the thousand-mile-long Fangxian County at the back of Wudang Mountain to explore the little-known Jiushi Rock and trace the secret to the longevity of the legendary "Sleeping Immortal" Chen Tuan.