Introduction to Hongyan Valley: Hongyan Valley is located on the west bank of the Mianxi River Grand Canyon, with a total length of about 4 kilometers. There are nearly 10 red caves on the mountainside, hence the name Hongyangou. According to legend, Taishang Laojun saw that the environment here was quiet and there were caves to live in, so he went to the cave here to refine elixirs.