The rocks that are joined together are natural. Some and not all of the perfectly round ones could of been created by ancient man. They did use those types and it is not completely unheard of finding many of them in one place. I talked to a guy that claims he has over 300 game balls all white except 1 which he says is black. All found in one area. I believe him due to the fact I know of somebody else who has 2 white game balls found in the same area which I have seen and held.