aliens / history
300 Million Year Old Machinery Found in Russia, Experts Say Aluminum Gear Not the Result of Natural Forces, Maybe Extraterrestrial | Beyond Science | Before It's News
Another strange artifact that was found in coal is the iron pot shown below. It was found in 1912 in Oklahoma in a piece of coal with an estimated age of 312 million years.
Unexplained Mysteries around the world
It is suggested by some cryptologists and others that crop circles are depicted in prehistoric stone and wall carvings, such as in the spiral patterns carved in a stone at Newgrange in Ireland. For those that hold the view that crop circles are created by extra-terrestrials in spacecraft, some would say that reasonable recorded proof of this is depicted in some ancient Egyptian pictures.