Who was the person who couldn't come down from Huashan Mountain in ancient China?

Legend:

From the north peak to the south, we broke through the dangerous places such as "Fairy Edge", "Ladder" and "Yan Wangbian" and came to a ridge called "Black Dragon Ridge", which was dozens of feet long and only over 2 feet wide. There are steep cliffs on both sides here, and only this stone ridge leads to the other side. If people walk in it, they will feel scared. Fortunately, there are railings on both sides. Just hold the railing and walk slowly without looking at dangerous places. There is a Hanyu Bookstore here. It was Han Yu, a great writer in the Tang Dynasty, who swam to Huashan and finally got up the courage to climb the "Black Dragon Ridge". Looking back, he was shocked. The mountain road was so dangerous. Thinking that he might not go back this time, he wrote a suicide note and threw it into the mountain stream. The cliff here is engraved with the words "Hanyu Calligraphy Office". This story is probably made up by later generations, but it vividly expresses the danger of this situation. After passing the "Black Dragon Ridge", you can reach Nanfeng, the highest peak of Huashan Mountain. Then come down from Nanfeng and go to Dongfeng and Zhongfeng. There are also many dangerous roads. It's amazing how many empty piles and badminton flips there are in Huashan. Be careful step by step. According to Cai Jun, an old dragon who has personally been to these two dangerous places, he reported face to face that he returned to his place of accommodation and was awakened twice in the middle of the night, both of which were "scared" by the dangers he saw during the day. Due to the unfortunate incidents of people falling off cliffs from time to time in Huashan Mountain, relevant departments have widened roads and increased protective facilities in the most dangerous places. In some places, there are uphill and downhill roads, which make climbers feel more secure.