Yep! and rebar, According to: Chariots of The Gods by Erich von Däniken They had help from aliens too. A fabulous book by the way. I read it as a teenager

Yep! and rebar, According to: Chariots of The Gods by Erich von Däniken They had help from aliens too. A fabulous book by the way. I read it as a teenager in the early 70's.