Introduction to the One-line Sky: Legend has it that the "One-line Sky" is actually a huge rock, and there lives a big poisonous snake underneath, which is harmful to the world. On a windy and rainy day, there was lightning and thunder, a loud noise shook the sky and the earth, a poisonous snake screamed for life, and a boulder split in half. Now people are in it, looking up eagerly, seeing the overhanging walls on both sides and a line of blue sky in the middle, which makes people imagine.