It is said that two mountains, Taihang and Wangwu, were connected together and created a blockage. They stood right in front of Yugong's house. The old man and his family had to tramp over mountains and hills to get in and out, which was particularly inconvenient. So 90-year old Yugong had a crazy idea: he and his family will move these mountains away. People thought he was old and insane!