Combine this site with "Out Of Place Artifacts", I can't help but think civilization has risen and fallen countless times in the past.
The Chinese have pottery in their museums that date back 12,000 years or so. They have no records of those times.
I’ve never found any of the so-called “out of place artifacts” very convincing at all. None of them have held up to any scientific scrutiny. Having said that, the ancient world history is probably a bit different than popularly supposed. Some sort of cataclysmic catastrophe seems probable.