Introduction to Sister-in-law Stone: Sister-in-law Stone looks like two sisters-in-law standing side by side when viewed from the east. Viewed from the west, it looks like they are about to fall. When General Feng Yuxiang led his troops to pass by this place, he was afraid that it would fall and hurt people. He tied the stone with iron ropes and used thirty horses to pull hard. As a result, the iron ropes broke but the stone did not move at all.