re: Ancient civilizations. Y or N?

Let's take the cities in Louisiana for example.

After 200 years, there will be very little evidence any of these cities existed if they were outright abandoned overnight, save for the larger and/or most robust concrete structures.

Now imagine 10,000 years. We'll be lucky if Baw is still worshipped as a mythical god. The slate will be wiped clean.

That's what happened to your ancients. The Earth itself erased them.