Introduction to the flagpole clip: The flagpole clip is made of two rectangular stones. It was built by Cao Pingzhang, the anti-Yuan general in the late Southern Song Dynasty, to hold the flag when he was camping in Nanyue Mountain. Legend has it that if a pregnant woman can pass between the flagpoles, the child will be a boy, and otherwise, the child will be a girl, so it is also called the "Children's Stone" and "Pregnancy Stone."