I dont beleive in both alien and god crap..if there is no explanation for process then credit goes to god and now you give credit to aliens. I think we do not have enough evidience to prove who made pyramid but there are lotta stuffs to wonder what they did in ancient times expecially in stone age...since there were not variety of communication  and physics,people still managed to make ancient sculptures in different civilization of human beings..instead of believing in myths believe in science and facts...there are and were hypothesis then and now in science..once its proved you are good to go.